/*!
 * Less - Leaner CSS v2.7.3
 * http://lesscss.org
 *
 * Copyright (c) 2009-2017, Alexis Sellier <self@cloudhead.net>
 * Licensed under the Apache-2.0 License.
 *
 */

/** * @license Apache-2.0
 */

(function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.less = f()}})(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
  var addDataAttr = require("./utils").addDataAttr,
    browser = require("./browser");

  module.exports = function(window, options) {

    // use options from the current script tag data attribues
    addDataAttr(options, browser.currentScript(window));

    if (options.isFileProtocol === undefined) {
      options.isFileProtocol = /^(file|(chrome|safari)(-extension)?|resource|qrc|app):/.test(window.location.protocol);
    }

    // Load styles asynchronously (default: false)
    //
    // This is set to `false` by default, so that the body
    // doesn't start loading before the stylesheets are parsed.
    // Setting this to `true` can result in flickering.
    //
    options.async = options.async || false;
    options.fileAsync = options.fileAsync || false;

    // Interval between watch polls
    options.poll = options.poll || (options.isFileProtocol ? 1000 : 1500);

    options.env = options.env || (window.location.hostname == '127.0.0.1' ||
    window.location.hostname == '0.0.0.0'   ||
    window.location.hostname == 'localhost' ||
    (window.location.port &&
      window.location.port.length > 0)      ||
    options.isFileProtocol                   ? 'development'
      : 'production');

    var dumpLineNumbers = /!dumpLineNumbers:(comments|mediaquery|all)/.exec(window.location.hash);
    if (dumpLineNumbers) {
      options.dumpLineNumbers = dumpLineNumbers[1];
    }

    if (options.useFileCache === undefined) {
      options.useFileCache = true;
    }

    if (options.onReady === undefined) {
      options.onReady = true;
    }

  };

},{"./browser":3,"./utils":10}],2:[function(require,module,exports){
  /**
   * Kicks off less and compiles any stylesheets
   * used in the browser distributed version of less
   * to kick-start less using the browser api
   */
  /*global window, document */

// shim Promise if required
  require('promise/polyfill.js');

  var options = window.less || {};
  require("./add-default-options")(window, options);

  var less = module.exports = require("./index")(window, options);

  window.less = less;

  var css, head, style;

// Always restore page visibility
  function resolveOrReject(data) {
    if (data.filename) {
      console.warn(data);
    }
    if (!options.async) {
      head.removeChild(style);
    }
  }

  if (options.onReady) {
    if (/!watch/.test(window.location.hash)) {
      less.watch();
    }
    // Simulate synchronous stylesheet loading by blocking page rendering
    if (!options.async) {
      css = 'body { display: none !important }';
      head = document.head || document.getElementsByTagName('head')[0];
      style = document.createElement('style');

      style.type = 'text/css';
      if (style.styleSheet) {
        style.styleSheet.cssText = css;
      } else {
        style.appendChild(document.createTextNode(css));
      }

      head.appendChild(style);
    }
    less.registerStylesheetsImmediately();
    less.pageLoadFinished = less.refresh(less.env === 'development').then(resolveOrReject, resolveOrReject);
  }

},{"./add-default-options":1,"./index":8,"promise/polyfill.js":97}],3:[function(require,module,exports){
  var utils = require("./utils");
  module.exports = {
    createCSS: function (document, styles, sheet) {
      // Strip the query-string
      var href = sheet.href || '';

      // If there is no title set, use the filename, minus the extension
      var id = 'less:' + (sheet.title || utils.extractId(href));

      // If this has already been inserted into the DOM, we may need to replace it
      var oldStyleNode = document.getElementById(id);
      var keepOldStyleNode = false;

      // Create a new stylesheet node for insertion or (if necessary) replacement
      var styleNode = document.createElement('style');
      styleNode.setAttribute('type', 'text/css');
      if (sheet.media) {
        styleNode.setAttribute('media', sheet.media);
      }
      styleNode.id = id;

      if (!styleNode.styleSheet) {
        styleNode.appendChild(document.createTextNode(styles));

        // If new contents match contents of oldStyleNode, don't replace oldStyleNode
        keepOldStyleNode = (oldStyleNode !== null && oldStyleNode.childNodes.length > 0 && styleNode.childNodes.length > 0 &&
          oldStyleNode.firstChild.nodeValue === styleNode.firstChild.nodeValue);
      }

      var head = document.getElementsByTagName('head')[0];

      // If there is no oldStyleNode, just append; otherwise, only append if we need
      // to replace oldStyleNode with an updated stylesheet
      if (oldStyleNode === null || keepOldStyleNode === false) {
        var nextEl = sheet && sheet.nextSibling || null;
        if (nextEl) {
          nextEl.parentNode.insertBefore(styleNode, nextEl);
        } else {
          head.appendChild(styleNode);
        }
      }
      if (oldStyleNode && keepOldStyleNode === false) {
        oldStyleNode.parentNode.removeChild(oldStyleNode);
      }

      // For IE.
      // This needs to happen *after* the style element is added to the DOM, otherwise IE 7 and 8 may crash.
      // See http://social.msdn.microsoft.com/Forums/en-US/7e081b65-878a-4c22-8e68-c10d39c2ed32/internet-explorer-crashes-appending-style-element-to-head
      if (styleNode.styleSheet) {
        try {
          styleNode.styleSheet.cssText = styles;
        } catch (e) {
          throw new Error("Couldn't reassign styleSheet.cssText.");
        }
      }
    },
    currentScript: function(window) {
      var document = window.document;
      return document.currentScript || (function() {
        var scripts = document.getElementsByTagName("script");
        return scripts[scripts.length - 1];
      })();
    }
  };

},{"./utils":10}],4:[function(require,module,exports){
// Cache system is a bit outdated and could do with work

  module.exports = function(window, options, logger) {
    var cache = null;
    if (options.env !== 'development') {
      try {
        cache = (typeof window.localStorage === 'undefined') ? null : window.localStorage;
      } catch (_) {}
    }
    return {
      setCSS: function(path, lastModified, modifyVars, styles) {
        if (cache) {
          logger.info('saving ' + path + ' to cache.');
          try {
            cache.setItem(path, styles);
            cache.setItem(path + ':timestamp', lastModified);
            if (modifyVars) {
              cache.setItem(path + ':vars', JSON.stringify(modifyVars));
            }
          } catch(e) {
            //TODO - could do with adding more robust error handling
            logger.error('failed to save "' + path + '" to local storage for caching.');
          }
        }
      },
      getCSS: function(path, webInfo, modifyVars) {
        var css       = cache && cache.getItem(path),
          timestamp = cache && cache.getItem(path + ':timestamp'),
          vars      = cache && cache.getItem(path + ':vars');

        modifyVars = modifyVars || {};

        if (timestamp && webInfo.lastModified &&
          (new Date(webInfo.lastModified).valueOf() ===
            new Date(timestamp).valueOf()) &&
          (!modifyVars && !vars || JSON.stringify(modifyVars) === vars)) {
          // Use local copy
          return css;
        }
      }
    };
  };

},{}],5:[function(require,module,exports){
  var utils = require("./utils"),
    browser = require("./browser");

  module.exports = function(window, less, options) {

    function errorHTML(e, rootHref) {
      var id = 'less-error-message:' + utils.extractId(rootHref || "");
      var template = '<li><label>{line}</label><pre class="{class}">{content}</pre></li>';
      var elem = window.document.createElement('div'), timer, content, errors = [];
      var filename = e.filename || rootHref;
      var filenameNoPath = filename.match(/([^\/]+(\?.*)?)$/)[1];

      elem.id        = id;
      elem.className = "less-error-message";

      content = '<h3>'  + (e.type || "Syntax") + "Error: " + (e.message || 'There is an error in your .less file') +
        '</h3>' + '<p>in <a href="' + filename   + '">' + filenameNoPath + "</a> ";

      var errorline = function (e, i, classname) {
        if (e.extract[i] !== undefined) {
          errors.push(template.replace(/\{line\}/, (parseInt(e.line, 10) || 0) + (i - 1))
            .replace(/\{class\}/, classname)
            .replace(/\{content\}/, e.extract[i]));
        }
      };

      if (e.extract) {
        errorline(e, 0, '');
        errorline(e, 1, 'line');
        errorline(e, 2, '');
        content += 'on line ' + e.line + ', column ' + (e.column + 1) + ':</p>' +
          '<ul>' + errors.join('') + '</ul>';
      }
      if (e.stack && (e.extract || options.logLevel >= 4)) {
        content += '<br/>Stack Trace</br />' + e.stack.split('\n').slice(1).join('<br/>');
      }
      elem.innerHTML = content;

      // CSS for error messages
      browser.createCSS(window.document, [
        '.less-error-message ul, .less-error-message li {',
        'list-style-type: none;',
        'margin-right: 15px;',
        'padding: 4px 0;',
        'margin: 0;',
        '}',
        '.less-error-message label {',
        'font-size: 12px;',
        'margin-right: 15px;',
        'padding: 4px 0;',
        'color: #cc7777;',
        '}',
        '.less-error-message pre {',
        'color: #dd6666;',
        'padding: 4px 0;',
        'margin: 0;',
        'display: inline-block;',
        '}',
        '.less-error-message pre.line {',
        'color: #ff0000;',
        '}',
        '.less-error-message h3 {',
        'font-size: 20px;',
        'font-weight: bold;',
        'padding: 15px 0 5px 0;',
        'margin: 0;',
        '}',
        '.less-error-message a {',
        'color: #10a',
        '}',
        '.less-error-message .error {',
        'color: red;',
        'font-weight: bold;',
        'padding-bottom: 2px;',
        'border-bottom: 1px dashed red;',
        '}'
      ].join('\n'), { title: 'error-message' });

      elem.style.cssText = [
        "font-family: Arial, sans-serif",
        "border: 1px solid #e00",
        "background-color: #eee",
        "border-radius: 5px",
        "-webkit-border-radius: 5px",
        "-moz-border-radius: 5px",
        "color: #e00",
        "padding: 15px",
        "margin-bottom: 15px"
      ].join(';');

      if (options.env === 'development') {
        timer = setInterval(function () {
          var document = window.document,
            body = document.body;
          if (body) {
            if (document.getElementById(id)) {
              body.replaceChild(elem, document.getElementById(id));
            } else {
              body.insertBefore(elem, body.firstChild);
            }
            clearInterval(timer);
          }
        }, 10);
      }
    }

    function removeErrorHTML(path) {
      var node = window.document.getElementById('less-error-message:' + utils.extractId(path));
      if (node) {
        node.parentNode.removeChild(node);
      }
    }

    function removeErrorConsole(path) {
      //no action
    }

    function removeError(path) {
      if (!options.errorReporting || options.errorReporting === "html") {
        removeErrorHTML(path);
      } else if (options.errorReporting === "console") {
        removeErrorConsole(path);
      } else if (typeof options.errorReporting === 'function') {
        options.errorReporting("remove", path);
      }
    }

    function errorConsole(e, rootHref) {
      var template = '{line} {content}';
      var filename = e.filename || rootHref;
      var errors = [];
      var content = (e.type || "Syntax") + "Error: " + (e.message || 'There is an error in your .less file') +
        " in " + filename + " ";

      var errorline = function (e, i, classname) {
        if (e.extract[i] !== undefined) {
          errors.push(template.replace(/\{line\}/, (parseInt(e.line, 10) || 0) + (i - 1))
            .replace(/\{class\}/, classname)
            .replace(/\{content\}/, e.extract[i]));
        }
      };

      if (e.extract) {
        errorline(e, 0, '');
        errorline(e, 1, 'line');
        errorline(e, 2, '');
        content += 'on line ' + e.line + ', column ' + (e.column + 1) + ':\n' +
          errors.join('\n');
      }
      if (e.stack && (e.extract || options.logLevel >= 4)) {
        content += '\nStack Trace\n' + e.stack;
      }
      less.logger.error(content);
    }

    function error(e, rootHref) {
      if (!options.errorReporting || options.errorReporting === "html") {
        errorHTML(e, rootHref);
      } else if (options.errorReporting === "console") {
        errorConsole(e, rootHref);
      } else if (typeof options.errorReporting === 'function') {
        options.errorReporting("add", e, rootHref);
      }
    }

    return {
      add: error,
      remove: removeError
    };
  };

},{"./browser":3,"./utils":10}],6:[function(require,module,exports){
  /*global window, XMLHttpRequest */

  module.exports = function(options, logger) {

    var AbstractFileManager = require("../less/environment/abstract-file-manager.js");

    var fileCache = {};

    //TODOS - move log somewhere. pathDiff and doing something similar in node. use pathDiff in the other browser file for the initial load

    function getXMLHttpRequest() {
      if (window.XMLHttpRequest && (window.location.protocol !== "file:" || !("ActiveXObject" in window))) {
        return new XMLHttpRequest();
      } else {
        try {
          /*global ActiveXObject */
          return new ActiveXObject("Microsoft.XMLHTTP");
        } catch (e) {
          logger.error("browser doesn't support AJAX.");
          return null;
        }
      }
    }

    var FileManager = function() {
    };

    FileManager.prototype = new AbstractFileManager();

    FileManager.prototype.alwaysMakePathsAbsolute = function alwaysMakePathsAbsolute() {
      return true;
    };
    FileManager.prototype.join = function join(basePath, laterPath) {
      if (!basePath) {
        return laterPath;
      }
      return this.extractUrlParts(laterPath, basePath).path;
    };
    FileManager.prototype.doXHR = function doXHR(url, type, callback, errback) {

      var xhr = getXMLHttpRequest();
      var async = options.isFileProtocol ? options.fileAsync : true;

      if (typeof xhr.overrideMimeType === 'function') {
        xhr.overrideMimeType('text/css');
      }
      logger.debug("XHR: Getting '" + url + "'");
      xhr.open('GET', url, async);
      xhr.setRequestHeader('Accept', type || 'text/x-less, text/css; q=0.9, */*; q=0.5');
      xhr.send(null);

      function handleResponse(xhr, callback, errback) {
        if (xhr.status >= 200 && xhr.status < 300) {
          callback(xhr.responseText,
            xhr.getResponseHeader("Last-Modified"));
        } else if (typeof errback === 'function') {
          errback(xhr.status, url);
        }
      }

      if (options.isFileProtocol && !options.fileAsync) {
        if (xhr.status === 0 || (xhr.status >= 200 && xhr.status < 300)) {
          callback(xhr.responseText);
        } else {
          errback(xhr.status, url);
        }
      } else if (async) {
        xhr.onreadystatechange = function () {
          if (xhr.readyState == 4) {
            handleResponse(xhr, callback, errback);
          }
        };
      } else {
        handleResponse(xhr, callback, errback);
      }
    };
    FileManager.prototype.supports = function(filename, currentDirectory, options, environment) {
      return true;
    };

    FileManager.prototype.clearFileCache = function() {
      fileCache = {};
    };

    FileManager.prototype.loadFile = function loadFile(filename, currentDirectory, options, environment, callback) {
      if (currentDirectory && !this.isPathAbsolute(filename)) {
        filename = currentDirectory + filename;
      }

      options = options || {};

      // sheet may be set to the stylesheet for the initial load or a collection of properties including
      // some context variables for imports
      var hrefParts = this.extractUrlParts(filename, window.location.href);
      var href      = hrefParts.url;

      if (options.useFileCache && fileCache[href]) {
        try {
          var lessText = fileCache[href];
          callback(null, { contents: lessText, filename: href, webInfo: { lastModified: new Date() }});
        } catch (e) {
          callback({filename: href, message: "Error loading file " + href + " error was " + e.message});
        }
        return;
      }

      this.doXHR(href, options.mime, function doXHRCallback(data, lastModified) {
        // per file cache
        fileCache[href] = data;

        // Use remote copy (re-parse)
        callback(null, { contents: data, filename: href, webInfo: { lastModified: lastModified }});
      }, function doXHRError(status, url) {
        callback({ type: 'File', message: "'" + url + "' wasn't found (" + status + ")", href: href });
      });
    };

    return FileManager;
  };

},{"../less/environment/abstract-file-manager.js":15}],7:[function(require,module,exports){
  module.exports = function() {

    var functionRegistry = require("./../less/functions/function-registry");

    function imageSize() {
      throw {
        type: "Runtime",
        message: "Image size functions are not supported in browser version of less"
      };
    }

    var imageFunctions = {
      "image-size": function(filePathNode) {
        imageSize(this, filePathNode);
        return -1;
      },
      "image-width": function(filePathNode) {
        imageSize(this, filePathNode);
        return -1;
      },
      "image-height": function(filePathNode) {
        imageSize(this, filePathNode);
        return -1;
      }
    };

    functionRegistry.addMultiple(imageFunctions);
  };

},{"./../less/functions/function-registry":22}],8:[function(require,module,exports){
//
// index.js
// Should expose the additional browser functions on to the less object
//
  var addDataAttr = require("./utils").addDataAttr,
    browser = require("./browser");

  module.exports = function(window, options) {
    var document = window.document;
    var less = require('../less')();

    //module.exports = less;
    less.options = options;
    var environment = less.environment,
      FileManager = require("./file-manager")(options, less.logger),
      fileManager = new FileManager();
    environment.addFileManager(fileManager);
    less.FileManager = FileManager;

    require("./log-listener")(less, options);
    var errors = require("./error-reporting")(window, less, options);
    var cache = less.cache = options.cache || require("./cache")(window, options, less.logger);
    require('./image-size')(less.environment);

    //Setup user functions
    if (options.functions) {
      less.functions.functionRegistry.addMultiple(options.functions);
    }

    var typePattern = /^text\/(x-)?less$/;

    function postProcessCSS(styles) { // deprecated, use a plugin for postprocesstasks
      if (options.postProcessor && typeof options.postProcessor === 'function') {
        styles = options.postProcessor.call(styles, styles) || styles;
      }
      return styles;
    }

    function clone(obj) {
      var cloned = {};
      for (var prop in obj) {
        if (obj.hasOwnProperty(prop)) {
          cloned[prop] = obj[prop];
        }
      }
      return cloned;
    }

    // only really needed for phantom
    function bind(func, thisArg) {
      var curryArgs = Array.prototype.slice.call(arguments, 2);
      return function() {
        var args = curryArgs.concat(Array.prototype.slice.call(arguments, 0));
        return func.apply(thisArg, args);
      };
    }

    function loadStyles(modifyVars) {
      var styles = document.getElementsByTagName('style'),
        style;

      for (var i = 0; i < styles.length; i++) {
        style = styles[i];
        if (style.type.match(typePattern)) {
          var instanceOptions = clone(options);
          instanceOptions.modifyVars = modifyVars;
          var lessText = style.innerHTML || '';
          instanceOptions.filename = document.location.href.replace(/#.*$/, '');

          /*jshint loopfunc:true */
          // use closure to store current style
          less.render(lessText, instanceOptions,
            bind(function(style, e, result) {
              if (e) {
                errors.add(e, "inline");
              } else {
                style.type = 'text/css';
                if (style.styleSheet) {
                  style.styleSheet.cssText = result.css;
                } else {
                  style.innerHTML = result.css;
                }
              }
            }, null, style));
        }
      }
    }

    function loadStyleSheet(sheet, callback, reload, remaining, modifyVars) {

      var instanceOptions = clone(options);
      addDataAttr(instanceOptions, sheet);
      instanceOptions.mime = sheet.type;

      if (modifyVars) {
        instanceOptions.modifyVars = modifyVars;
      }

      function loadInitialFileCallback(loadedFile) {

        var data = loadedFile.contents,
          path = loadedFile.filename,
          webInfo = loadedFile.webInfo;

        var newFileInfo = {
          currentDirectory: fileManager.getPath(path),
          filename: path,
          rootFilename: path,
          relativeUrls: instanceOptions.relativeUrls};

        newFileInfo.entryPath = newFileInfo.currentDirectory;
        newFileInfo.rootpath = instanceOptions.rootpath || newFileInfo.currentDirectory;

        if (webInfo) {
          webInfo.remaining = remaining;

          var css = cache.getCSS(path, webInfo, instanceOptions.modifyVars);
          if (!reload && css) {
            webInfo.local = true;
            callback(null, css, data, sheet, webInfo, path);
            return;
          }

        }

        //TODO add tests around how this behaves when reloading
        errors.remove(path);

        instanceOptions.rootFileInfo = newFileInfo;
        less.render(data, instanceOptions, function(e, result) {
          if (e) {
            e.href = path;
            callback(e);
          } else {
            result.css = postProcessCSS(result.css);
            cache.setCSS(sheet.href, webInfo.lastModified, instanceOptions.modifyVars, result.css);
            callback(null, result.css, data, sheet, webInfo, path);
          }
        });
      }

      fileManager.loadFile(sheet.href, null, instanceOptions, environment, function(e, loadedFile) {
        if (e) {
          callback(e);
          return;
        }
        loadInitialFileCallback(loadedFile);
      });
    }

    function loadStyleSheets(callback, reload, modifyVars) {
      for (var i = 0; i < less.sheets.length; i++) {
        loadStyleSheet(less.sheets[i], callback, reload, less.sheets.length - (i + 1), modifyVars);
      }
    }

    function initRunningMode() {
      if (less.env === 'development') {
        less.watchTimer = setInterval(function () {
          if (less.watchMode) {
            fileManager.clearFileCache();
            loadStyleSheets(function (e, css, _, sheet, webInfo) {
              if (e) {
                errors.add(e, e.href || sheet.href);
              } else if (css) {
                browser.createCSS(window.document, css, sheet);
              }
            });
          }
        }, options.poll);
      }
    }

    //
    // Watch mode
    //
    less.watch   = function () {
      if (!less.watchMode ) {
        less.env = 'development';
        initRunningMode();
      }
      this.watchMode = true;
      return true;
    };

    less.unwatch = function () {clearInterval(less.watchTimer); this.watchMode = false; return false; };

    //
    // Synchronously get all <link> tags with the 'rel' attribute set to
    // "stylesheet/less".
    //
    less.registerStylesheetsImmediately = function() {
      var links = document.getElementsByTagName('link');
      less.sheets = [];

      for (var i = 0; i < links.length; i++) {
        if (links[i].rel === 'stylesheet/less' || (links[i].rel.match(/stylesheet/) &&
            (links[i].type.match(typePattern)))) {
          less.sheets.push(links[i]);
        }
      }
    };

    //
    // Asynchronously get all <link> tags with the 'rel' attribute set to
    // "stylesheet/less", returning a Promise.
    //
    less.registerStylesheets = function() {
      return new Promise(function(resolve, reject) {
        less.registerStylesheetsImmediately();
        resolve();
      });
    };

    //
    // With this function, it's possible to alter variables and re-render
    // CSS without reloading less-files
    //
    less.modifyVars = function(record) {
      return less.refresh(true, record, false);
    };

    less.refresh = function (reload, modifyVars, clearFileCache) {
      if ((reload || clearFileCache) && clearFileCache !== false) {
        fileManager.clearFileCache();
      }
      return new Promise(function (resolve, reject) {
        var startTime, endTime, totalMilliseconds, remainingSheets;
        startTime = endTime = new Date();

        // Set counter for remaining unprocessed sheets
        remainingSheets = less.sheets.length;

        if (remainingSheets === 0) {

          endTime = new Date();
          totalMilliseconds = endTime - startTime;
          less.logger.info("Less has finished and no sheets were loaded.");
          resolve({
            startTime: startTime,
            endTime: endTime,
            totalMilliseconds: totalMilliseconds,
            sheets: less.sheets.length
          });

        } else {
          // Relies on less.sheets array, callback seems to be guaranteed to be called for every element of the array
          loadStyleSheets(function (e, css, _, sheet, webInfo) {
            if (e) {
              errors.add(e, e.href || sheet.href);
              reject(e);
              return;
            }
            if (webInfo.local) {
              less.logger.info("Loading " + sheet.href + " from cache.");
            } else {
              less.logger.info("Rendered " + sheet.href + " successfully.");
            }
            browser.createCSS(window.document, css, sheet);
            less.logger.info("CSS for " + sheet.href + " generated in " + (new Date() - endTime) + 'ms');

            // Count completed sheet
            remainingSheets--;

            // Check if the last remaining sheet was processed and then call the promise
            if (remainingSheets === 0) {
              totalMilliseconds = new Date() - startTime;
              less.logger.info("Less has finished. CSS generated in " + totalMilliseconds + 'ms');
              resolve({
                startTime: startTime,
                endTime: endTime,
                totalMilliseconds: totalMilliseconds,
                sheets: less.sheets.length
              });
            }
            endTime = new Date();
          }, reload, modifyVars);
        }

        loadStyles(modifyVars);
      });
    };

    less.refreshStyles = loadStyles;
    return less;
  };

},{"../less":31,"./browser":3,"./cache":4,"./error-reporting":5,"./file-manager":6,"./image-size":7,"./log-listener":9,"./utils":10}],9:[function(require,module,exports){
  module.exports = function(less, options) {

    var logLevel_debug = 4,
      logLevel_info = 3,
      logLevel_warn = 2,
      logLevel_error = 1;

    // The amount of logging in the javascript console.
    // 3 - Debug, information and errors
    // 2 - Information and errors
    // 1 - Errors
    // 0 - None
    // Defaults to 2
    options.logLevel = typeof options.logLevel !== 'undefined' ? options.logLevel : (options.env === 'development' ?  logLevel_info : logLevel_error);

    if (!options.loggers) {
      options.loggers = [{
        debug: function(msg) {
          if (options.logLevel >= logLevel_debug) {
            console.log(msg);
          }
        },
        info: function(msg) {
          if (options.logLevel >= logLevel_info) {
            console.log(msg);
          }
        },
        warn: function(msg) {
          if (options.logLevel >= logLevel_warn) {
            console.warn(msg);
          }
        },
        error: function(msg) {
          if (options.logLevel >= logLevel_error) {
            console.error(msg);
          }
        }
      }];
    }
    for (var i = 0; i < options.loggers.length; i++) {
      less.logger.addListener(options.loggers[i]);
    }
  };

},{}],10:[function(require,module,exports){
  module.exports = {
    extractId: function(href) {
      return href.replace(/^[a-z-]+:\/+?[^\/]+/, '')  // Remove protocol & domain
        .replace(/[\?\&]livereload=\w+/, '')        // Remove LiveReload cachebuster
        .replace(/^\//, '')                         // Remove root /
        .replace(/\.[a-zA-Z]+$/, '')                // Remove simple extension
        .replace(/[^\.\w-]+/g, '-')                 // Replace illegal characters
        .replace(/\./g, ':');                       // Replace dots with colons(for valid id)
    },
    addDataAttr: function(options, tag) {
      for (var opt in tag.dataset) {
        if (tag.dataset.hasOwnProperty(opt)) {
          if (opt === "env" || opt === "dumpLineNumbers" || opt === "rootpath" || opt === "errorReporting") {
            options[opt] = tag.dataset[opt];
          } else {
            try {
              options[opt] = JSON.parse(tag.dataset[opt]);
            }
            catch(_) {}
          }
        }
      }
    }
  };

},{}],11:[function(require,module,exports){
  var contexts = {};
  module.exports = contexts;

  var copyFromOriginal = function copyFromOriginal(original, destination, propertiesToCopy) {
    if (!original) { return; }

    for (var i = 0; i < propertiesToCopy.length; i++) {
      if (original.hasOwnProperty(propertiesToCopy[i])) {
        destination[propertiesToCopy[i]] = original[propertiesToCopy[i]];
      }
    }
  };

  /*
 parse is used whilst parsing
 */
  var parseCopyProperties = [
    // options
    'paths',            // option - unmodified - paths to search for imports on
    'relativeUrls',     // option - whether to adjust URL's to be relative
    'rootpath',         // option - rootpath to append to URL's
    'strictImports',    // option -
    'insecure',         // option - whether to allow imports from insecure ssl hosts
    'dumpLineNumbers',  // option - whether to dump line numbers
    'compress',         // option - whether to compress
    'syncImport',       // option - whether to import synchronously
    'chunkInput',       // option - whether to chunk input. more performant but causes parse issues.
    'mime',             // browser only - mime type for sheet import
    'useFileCache',     // browser only - whether to use the per file session cache
    // context
    'processImports',   // option & context - whether to process imports. if false then imports will not be imported.
                        // Used by the import manager to stop multiple import visitors being created.
    'pluginManager'     // Used as the plugin manager for the session
  ];

  contexts.Parse = function(options) {
    copyFromOriginal(options, this, parseCopyProperties);

    if (typeof this.paths === "string") { this.paths = [this.paths]; }
  };

  var evalCopyProperties = [
    'paths',          // additional include paths
    'compress',       // whether to compress
    'ieCompat',       // whether to enforce IE compatibility (IE8 data-uri)
    'strictMath',     // whether math has to be within parenthesis
    'strictUnits',    // whether units need to evaluate correctly
    'sourceMap',      // whether to output a source map
    'importMultiple', // whether we are currently importing multiple copies
    'urlArgs',        // whether to add args into url tokens
    'javascriptEnabled',// option - whether JavaScript is enabled. if undefined, defaults to true
    'pluginManager',  // Used as the plugin manager for the session
    'importantScope'  // used to bubble up !important statements
  ];

  contexts.Eval = function(options, frames) {
    copyFromOriginal(options, this, evalCopyProperties);

    if (typeof this.paths === "string") { this.paths = [this.paths]; }

    this.frames = frames || [];
    this.importantScope = this.importantScope || [];
  };

  contexts.Eval.prototype.inParenthesis = function () {
    if (!this.parensStack) {
      this.parensStack = [];
    }
    this.parensStack.push(true);
  };

  contexts.Eval.prototype.outOfParenthesis = function () {
    this.parensStack.pop();
  };

  contexts.Eval.prototype.isMathOn = function () {
    return this.strictMath ? (this.parensStack && this.parensStack.length) : true;
  };

  contexts.Eval.prototype.isPathRelative = function (path) {
    return !/^(?:[a-z-]+:|\/|#)/i.test(path);
  };

  contexts.Eval.prototype.normalizePath = function( path ) {
    var
      segments = path.split("/").reverse(),
      segment;

    path = [];
    while (segments.length !== 0 ) {
      segment = segments.pop();
      switch( segment ) {
        case ".":
          break;
        case "..":
          if ((path.length === 0) || (path[path.length - 1] === "..")) {
            path.push( segment );
          } else {
            path.pop();
          }
          break;
        default:
          path.push( segment );
          break;
      }
    }

    return path.join("/");
  };

//todo - do the same for the toCSS ?

},{}],12:[function(require,module,exports){
  module.exports = {
    'aliceblue':'#f0f8ff',
    'antiquewhite':'#faebd7',
    'aqua':'#00ffff',
    'aquamarine':'#7fffd4',
    'azure':'#f0ffff',
    'beige':'#f5f5dc',
    'bisque':'#ffe4c4',
    'black':'#000000',
    'blanchedalmond':'#ffebcd',
    'blue':'#0000ff',
    'blueviolet':'#8a2be2',
    'brown':'#a52a2a',
    'burlywood':'#deb887',
    'cadetblue':'#5f9ea0',
    'chartreuse':'#7fff00',
    'chocolate':'#d2691e',
    'coral':'#ff7f50',
    'cornflowerblue':'#6495ed',
    'cornsilk':'#fff8dc',
    'crimson':'#dc143c',
    'cyan':'#00ffff',
    'darkblue':'#00008b',
    'darkcyan':'#008b8b',
    'darkgoldenrod':'#b8860b',
    'darkgray':'#a9a9a9',
    'darkgrey':'#a9a9a9',
    'darkgreen':'#006400',
    'darkkhaki':'#bdb76b',
    'darkmagenta':'#8b008b',
    'darkolivegreen':'#556b2f',
    'darkorange':'#ff8c00',
    'darkorchid':'#9932cc',
    'darkred':'#8b0000',
    'darksalmon':'#e9967a',
    'darkseagreen':'#8fbc8f',
    'darkslateblue':'#483d8b',
    'darkslategray':'#2f4f4f',
    'darkslategrey':'#2f4f4f',
    'darkturquoise':'#00ced1',
    'darkviolet':'#9400d3',
    'deeppink':'#ff1493',
    'deepskyblue':'#00bfff',
    'dimgray':'#696969',
    'dimgrey':'#696969',
    'dodgerblue':'#1e90ff',
    'firebrick':'#b22222',
    'floralwhite':'#fffaf0',
    'forestgreen':'#228b22',
    'fuchsia':'#ff00ff',
    'gainsboro':'#dcdcdc',
    'ghostwhite':'#f8f8ff',
    'gold':'#ffd700',
    'goldenrod':'#daa520',
    'gray':'#808080',
    'grey':'#808080',
    'green':'#008000',
    'greenyellow':'#adff2f',
    'honeydew':'#f0fff0',
    'hotpink':'#ff69b4',
    'indianred':'#cd5c5c',
    'indigo':'#4b0082',
    'ivory':'#fffff0',
    'khaki':'#f0e68c',
    'lavender':'#e6e6fa',
    'lavenderblush':'#fff0f5',
    'lawngreen':'#7cfc00',
    'lemonchiffon':'#fffacd',
    'lightblue':'#add8e6',
    'lightcoral':'#f08080',
    'lightcyan':'#e0ffff',
    'lightgoldenrodyellow':'#fafad2',
    'lightgray':'#d3d3d3',
    'lightgrey':'#d3d3d3',
    'lightgreen':'#90ee90',
    'lightpink':'#ffb6c1',
    'lightsalmon':'#ffa07a',
    'lightseagreen':'#20b2aa',
    'lightskyblue':'#87cefa',
    'lightslategray':'#778899',
    'lightslategrey':'#778899',
    'lightsteelblue':'#b0c4de',
    'lightyellow':'#ffffe0',
    'lime':'#00ff00',
    'limegreen':'#32cd32',
    'linen':'#faf0e6',
    'magenta':'#ff00ff',
    'maroon':'#800000',
    'mediumaquamarine':'#66cdaa',
    'mediumblue':'#0000cd',
    'mediumorchid':'#ba55d3',
    'mediumpurple':'#9370d8',
    'mediumseagreen':'#3cb371',
    'mediumslateblue':'#7b68ee',
    'mediumspringgreen':'#00fa9a',
    'mediumturquoise':'#48d1cc',
    'mediumvioletred':'#c71585',
    'midnightblue':'#191970',
    'mintcream':'#f5fffa',
    'mistyrose':'#ffe4e1',
    'moccasin':'#ffe4b5',
    'navajowhite':'#ffdead',
    'navy':'#000080',
    'oldlace':'#fdf5e6',
    'olive':'#808000',
    'olivedrab':'#6b8e23',
    'orange':'#ffa500',
    'orangered':'#ff4500',
    'orchid':'#da70d6',
    'palegoldenrod':'#eee8aa',
    'palegreen':'#98fb98',
    'paleturquoise':'#afeeee',
    'palevioletred':'#d87093',
    'papayawhip':'#ffefd5',
    'peachpuff':'#ffdab9',
    'peru':'#cd853f',
    'pink':'#ffc0cb',
    'plum':'#dda0dd',
    'powderblue':'#b0e0e6',
    'purple':'#800080',
    'rebeccapurple':'#663399',
    'red':'#ff0000',
    'rosybrown':'#bc8f8f',
    'royalblue':'#4169e1',
    'saddlebrown':'#8b4513',
    'salmon':'#fa8072',
    'sandybrown':'#f4a460',
    'seagreen':'#2e8b57',
    'seashell':'#fff5ee',
    'sienna':'#a0522d',
    'silver':'#c0c0c0',
    'skyblue':'#87ceeb',
    'slateblue':'#6a5acd',
    'slategray':'#708090',
    'slategrey':'#708090',
    'snow':'#fffafa',
    'springgreen':'#00ff7f',
    'steelblue':'#4682b4',
    'tan':'#d2b48c',
    'teal':'#008080',
    'thistle':'#d8bfd8',
    'tomato':'#ff6347',
    'turquoise':'#40e0d0',
    'violet':'#ee82ee',
    'wheat':'#f5deb3',
    'white':'#ffffff',
    'whitesmoke':'#f5f5f5',
    'yellow':'#ffff00',
    'yellowgreen':'#9acd32'
  };
},{}],13:[function(require,module,exports){
  module.exports = {
    colors: require("./colors"),
    unitConversions: require("./unit-conversions")
  };

},{"./colors":12,"./unit-conversions":14}],14:[function(require,module,exports){
  module.exports = {
    length: {
      'm': 1,
      'cm': 0.01,
      'mm': 0.001,
      'in': 0.0254,
      'px': 0.0254 / 96,
      'pt': 0.0254 / 72,
      'pc': 0.0254 / 72 * 12
    },
    duration: {
      's': 1,
      'ms': 0.001
    },
    angle: {
      'rad': 1 / (2 * Math.PI),
      'deg': 1 / 360,
      'grad': 1 / 400,
      'turn': 1
    }
  };
},{}],15:[function(require,module,exports){
  var abstractFileManager = function() {
  };

  abstractFileManager.prototype.getPath = function (filename) {
    var j = filename.lastIndexOf('?');
    if (j > 0) {
      filename = filename.slice(0, j);
    }
    j = filename.lastIndexOf('/');
    if (j < 0) {
      j = filename.lastIndexOf('\\');
    }
    if (j < 0) {
      return "";
    }
    return filename.slice(0, j + 1);
  };

  abstractFileManager.prototype.tryAppendExtension = function(path, ext) {
    return /(\.[a-z]*$)|([\?;].*)$/.test(path) ? path : path + ext;
  };

  abstractFileManager.prototype.tryAppendLessExtension = function(path) {
    return this.tryAppendExtension(path, '.less');
  };

  abstractFileManager.prototype.supportsSync = function() {
    return false;
  };

  abstractFileManager.prototype.alwaysMakePathsAbsolute = function() {
    return false;
  };

  abstractFileManager.prototype.isPathAbsolute = function(filename) {
    return (/^(?:[a-z-]+:|\/|\\|#)/i).test(filename);
  };

  abstractFileManager.prototype.join = function(basePath, laterPath) {
    if (!basePath) {
      return laterPath;
    }
    return basePath + laterPath;
  };
  abstractFileManager.prototype.pathDiff = function pathDiff(url, baseUrl) {
    // diff between two paths to create a relative path

    var urlParts = this.extractUrlParts(url),
      baseUrlParts = this.extractUrlParts(baseUrl),
      i, max, urlDirectories, baseUrlDirectories, diff = "";
    if (urlParts.hostPart !== baseUrlParts.hostPart) {
      return "";
    }
    max = Math.max(baseUrlParts.directories.length, urlParts.directories.length);
    for (i = 0; i < max; i++) {
      if (baseUrlParts.directories[i] !== urlParts.directories[i]) { break; }
    }
    baseUrlDirectories = baseUrlParts.directories.slice(i);
    urlDirectories = urlParts.directories.slice(i);
    for (i = 0; i < baseUrlDirectories.length - 1; i++) {
      diff += "../";
    }
    for (i = 0; i < urlDirectories.length - 1; i++) {
      diff += urlDirectories[i] + "/";
    }
    return diff;
  };
// helper function, not part of API
  abstractFileManager.prototype.extractUrlParts = function extractUrlParts(url, baseUrl) {
    // urlParts[1] = protocol://hostname/ OR /
    // urlParts[2] = / if path relative to host base
    // urlParts[3] = directories
    // urlParts[4] = filename
    // urlParts[5] = parameters

    var urlPartsRegex = /^((?:[a-z-]+:)?\/{2}(?:[^\/\?#]*\/)|([\/\\]))?((?:[^\/\\\?#]*[\/\\])*)([^\/\\\?#]*)([#\?].*)?$/i,
      urlParts = url.match(urlPartsRegex),
      returner = {}, directories = [], i, baseUrlParts;

    if (!urlParts) {
      throw new Error("Could not parse sheet href - '" + url + "'");
    }

    // Stylesheets in IE don't always return the full path
    if (baseUrl && (!urlParts[1] || urlParts[2])) {
      baseUrlParts = baseUrl.match(urlPartsRegex);
      if (!baseUrlParts) {
        throw new Error("Could not parse page url - '" + baseUrl + "'");
      }
      urlParts[1] = urlParts[1] || baseUrlParts[1] || "";
      if (!urlParts[2]) {
        urlParts[3] = baseUrlParts[3] + urlParts[3];
      }
    }

    if (urlParts[3]) {
      directories = urlParts[3].replace(/\\/g, "/").split("/");

      // extract out . before .. so .. doesn't absorb a non-directory
      for (i = 0; i < directories.length; i++) {
        if (directories[i] === ".") {
          directories.splice(i, 1);
          i -= 1;
        }
      }

      for (i = 0; i < directories.length; i++) {
        if (directories[i] === ".." && i > 0) {
          directories.splice(i - 1, 2);
          i -= 2;
        }
      }
    }

    returner.hostPart = urlParts[1];
    returner.directories = directories;
    returner.path = (urlParts[1] || "") + directories.join("/");
    returner.fileUrl = returner.path + (urlParts[4] || "");
    returner.url = returner.fileUrl + (urlParts[5] || "");
    return returner;
  };

  module.exports = abstractFileManager;

},{}],16:[function(require,module,exports){
  var logger = require("../logger");
  var environment = function(externalEnvironment, fileManagers) {
    this.fileManagers = fileManagers || [];
    externalEnvironment = externalEnvironment || {};

    var optionalFunctions = ["encodeBase64", "mimeLookup", "charsetLookup", "getSourceMapGenerator"],
      requiredFunctions = [],
      functions = requiredFunctions.concat(optionalFunctions);

    for (var i = 0; i < functions.length; i++) {
      var propName = functions[i],
        environmentFunc = externalEnvironment[propName];
      if (environmentFunc) {
        this[propName] = environmentFunc.bind(externalEnvironment);
      } else if (i < requiredFunctions.length) {
        this.warn("missing required function in environment - " + propName);
      }
    }
  };

  environment.prototype.getFileManager = function (filename, currentDirectory, options, environment, isSync) {

    if (!filename) {
      logger.warn("getFileManager called with no filename.. Please report this issue. continuing.");
    }
    if (currentDirectory == null) {
      logger.warn("getFileManager called with null directory.. Please report this issue. continuing.");
    }

    var fileManagers = this.fileManagers;
    if (options.pluginManager) {
      fileManagers = [].concat(fileManagers).concat(options.pluginManager.getFileManagers());
    }
    for (var i = fileManagers.length - 1; i >= 0 ; i--) {
      var fileManager = fileManagers[i];
      if (fileManager[isSync ? "supportsSync" : "supports"](filename, currentDirectory, options, environment)) {
        return fileManager;
      }
    }
    return null;
  };

  environment.prototype.addFileManager = function (fileManager) {
    this.fileManagers.push(fileManager);
  };

  environment.prototype.clearFileManagers = function () {
    this.fileManagers = [];
  };

  module.exports = environment;

},{"../logger":33}],17:[function(require,module,exports){
  var Color = require("../tree/color"),
    functionRegistry = require("./function-registry");

// Color Blending
// ref: http://www.w3.org/TR/compositing-1

  function colorBlend(mode, color1, color2) {
    var ab = color1.alpha, cb, // backdrop
      as = color2.alpha, cs, // source
      ar, cr, r = [];        // result

    ar = as + ab * (1 - as);
    for (var i = 0; i < 3; i++) {
      cb = color1.rgb[i] / 255;
      cs = color2.rgb[i] / 255;
      cr = mode(cb, cs);
      if (ar) {
        cr = (as * cs + ab * (cb -
          as * (cb + cs - cr))) / ar;
      }
      r[i] = cr * 255;
    }

    return new Color(r, ar);
  }

  var colorBlendModeFunctions = {
    multiply: function(cb, cs) {
      return cb * cs;
    },
    screen: function(cb, cs) {
      return cb + cs - cb * cs;
    },
    overlay: function(cb, cs) {
      cb *= 2;
      return (cb <= 1) ?
        colorBlendModeFunctions.multiply(cb, cs) :
        colorBlendModeFunctions.screen(cb - 1, cs);
    },
    softlight: function(cb, cs) {
      var d = 1, e = cb;
      if (cs > 0.5) {
        e = 1;
        d = (cb > 0.25) ? Math.sqrt(cb)
          : ((16 * cb - 12) * cb + 4) * cb;
      }
      return cb - (1 - 2 * cs) * e * (d - cb);
    },
    hardlight: function(cb, cs) {
      return colorBlendModeFunctions.overlay(cs, cb);
    },
    difference: function(cb, cs) {
      return Math.abs(cb - cs);
    },
    exclusion: function(cb, cs) {
      return cb + cs - 2 * cb * cs;
    },

    // non-w3c functions:
    average: function(cb, cs) {
      return (cb + cs) / 2;
    },
    negation: function(cb, cs) {
      return 1 - Math.abs(cb + cs - 1);
    }
  };

  for (var f in colorBlendModeFunctions) {
    if (colorBlendModeFunctions.hasOwnProperty(f)) {
      colorBlend[f] = colorBlend.bind(null, colorBlendModeFunctions[f]);
    }
  }

  functionRegistry.addMultiple(colorBlend);

},{"../tree/color":50,"./function-registry":22}],18:[function(require,module,exports){
  var Dimension = require("../tree/dimension"),
    Color = require("../tree/color"),
    Quoted = require("../tree/quoted"),
    Anonymous = require("../tree/anonymous"),
    functionRegistry = require("./function-registry"),
    colorFunctions;

  function clamp(val) {
    return Math.min(1, Math.max(0, val));
  }
  function hsla(color) {
    return colorFunctions.hsla(color.h, color.s, color.l, color.a);
  }
  function number(n) {
    if (n instanceof Dimension) {
      return parseFloat(n.unit.is('%') ? n.value / 100 : n.value);
    } else if (typeof n === 'number') {
      return n;
    } else {
      throw {
        type: "Argument",
        message: "color functions take numbers as parameters"
      };
    }
  }
  function scaled(n, size) {
    if (n instanceof Dimension && n.unit.is('%')) {
      return parseFloat(n.value * size / 100);
    } else {
      return number(n);
    }
  }
  colorFunctions = {
    rgb: function (r, g, b) {
      return colorFunctions.rgba(r, g, b, 1.0);
    },
    rgba: function (r, g, b, a) {
      var rgb = [r, g, b].map(function (c) { return scaled(c, 255); });
      a = number(a);
      return new Color(rgb, a);
    },
    hsl: function (h, s, l) {
      return colorFunctions.hsla(h, s, l, 1.0);
    },
    hsla: function (h, s, l, a) {

      var m1, m2;

      function hue(h) {
        h = h < 0 ? h + 1 : (h > 1 ? h - 1 : h);
        if (h * 6 < 1) {
          return m1 + (m2 - m1) * h * 6;
        }
        else if (h * 2 < 1) {
          return m2;
        }
        else if (h * 3 < 2) {
          return m1 + (m2 - m1) * (2 / 3 - h) * 6;
        }
        else {
          return m1;
        }
      }

      h = (number(h) % 360) / 360;
      s = clamp(number(s)); l = clamp(number(l)); a = clamp(number(a));

      m2 = l <= 0.5 ? l * (s + 1) : l + s - l * s;
      m1 = l * 2 - m2;

      return colorFunctions.rgba(hue(h + 1 / 3) * 255,
        hue(h)       * 255,
        hue(h - 1 / 3) * 255,
        a);
    },

    hsv: function(h, s, v) {
      return colorFunctions.hsva(h, s, v, 1.0);
    },

    hsva: function(h, s, v, a) {
      h = ((number(h) % 360) / 360) * 360;
      s = number(s); v = number(v); a = number(a);

      var i, f;
      i = Math.floor((h / 60) % 6);
      f = (h / 60) - i;

      var vs = [v,
        v * (1 - s),
        v * (1 - f * s),
        v * (1 - (1 - f) * s)];
      var perm = [[0, 3, 1],
        [2, 0, 1],
        [1, 0, 3],
        [1, 2, 0],
        [3, 1, 0],
        [0, 1, 2]];

      return colorFunctions.rgba(vs[perm[i][0]] * 255,
        vs[perm[i][1]] * 255,
        vs[perm[i][2]] * 255,
        a);
    },

    hue: function (color) {
      return new Dimension(color.toHSL().h);
    },
    saturation: function (color) {
      return new Dimension(color.toHSL().s * 100, '%');
    },
    lightness: function (color) {
      return new Dimension(color.toHSL().l * 100, '%');
    },
    hsvhue: function(color) {
      return new Dimension(color.toHSV().h);
    },
    hsvsaturation: function (color) {
      return new Dimension(color.toHSV().s * 100, '%');
    },
    hsvvalue: function (color) {
      return new Dimension(color.toHSV().v * 100, '%');
    },
    red: function (color) {
      return new Dimension(color.rgb[0]);
    },
    green: function (color) {
      return new Dimension(color.rgb[1]);
    },
    blue: function (color) {
      return new Dimension(color.rgb[2]);
    },
    alpha: function (color) {
      return new Dimension(color.toHSL().a);
    },
    luma: function (color) {
      return new Dimension(color.luma() * color.alpha * 100, '%');
    },
    luminance: function (color) {
      var luminance =
        (0.2126 * color.rgb[0] / 255) +
        (0.7152 * color.rgb[1] / 255) +
        (0.0722 * color.rgb[2] / 255);

      return new Dimension(luminance * color.alpha * 100, '%');
    },
    saturate: function (color, amount, method) {
      // filter: saturate(3.2);
      // should be kept as is, so check for color
      if (!color.rgb) {
        return null;
      }
      var hsl = color.toHSL();

      if (typeof method !== "undefined" && method.value === "relative") {
        hsl.s +=  hsl.s * amount.value / 100;
      }
      else {
        hsl.s += amount.value / 100;
      }
      hsl.s = clamp(hsl.s);
      return hsla(hsl);
    },
    desaturate: function (color, amount, method) {
      var hsl = color.toHSL();

      if (typeof method !== "undefined" && method.value === "relative") {
        hsl.s -=  hsl.s * amount.value / 100;
      }
      else {
        hsl.s -= amount.value / 100;
      }
      hsl.s = clamp(hsl.s);
      return hsla(hsl);
    },
    lighten: function (color, amount, method) {
      var hsl = color.toHSL();

      if (typeof method !== "undefined" && method.value === "relative") {
        hsl.l +=  hsl.l * amount.value / 100;
      }
      else {
        hsl.l += amount.value / 100;
      }
      hsl.l = clamp(hsl.l);
      return hsla(hsl);
    },
    darken: function (color, amount, method) {
      var hsl = color.toHSL();

      if (typeof method !== "undefined" && method.value === "relative") {
        hsl.l -=  hsl.l * amount.value / 100;
      }
      else {
        hsl.l -= amount.value / 100;
      }
      hsl.l = clamp(hsl.l);
      return hsla(hsl);
    },
    fadein: function (color, amount, method) {
      var hsl = color.toHSL();

      if (typeof method !== "undefined" && method.value === "relative") {
        hsl.a +=  hsl.a * amount.value / 100;
      }
      else {
        hsl.a += amount.value / 100;
      }
      hsl.a = clamp(hsl.a);
      return hsla(hsl);
    },
    fadeout: function (color, amount, method) {
      var hsl = color.toHSL();

      if (typeof method !== "undefined" && method.value === "relative") {
        hsl.a -=  hsl.a * amount.value / 100;
      }
      else {
        hsl.a -= amount.value / 100;
      }
      hsl.a = clamp(hsl.a);
      return hsla(hsl);
    },
    fade: function (color, amount) {
      var hsl = color.toHSL();

      hsl.a = amount.value / 100;
      hsl.a = clamp(hsl.a);
      return hsla(hsl);
    },
    spin: function (color, amount) {
      var hsl = color.toHSL();
      var hue = (hsl.h + amount.value) % 360;

      hsl.h = hue < 0 ? 360 + hue : hue;

      return hsla(hsl);
    },
    //
    // Copyright (c) 2006-2009 Hampton Catlin, Natalie Weizenbaum, and Chris Eppstein
    // http://sass-lang.com
    //
    mix: function (color1, color2, weight) {
      if (!color1.toHSL || !color2.toHSL) {
        console.log(color2.type);
        console.dir(color2);
      }
      if (!weight) {
        weight = new Dimension(50);
      }
      var p = weight.value / 100.0;
      var w = p * 2 - 1;
      var a = color1.toHSL().a - color2.toHSL().a;

      var w1 = (((w * a == -1) ? w : (w + a) / (1 + w * a)) + 1) / 2.0;
      var w2 = 1 - w1;

      var rgb = [color1.rgb[0] * w1 + color2.rgb[0] * w2,
        color1.rgb[1] * w1 + color2.rgb[1] * w2,
        color1.rgb[2] * w1 + color2.rgb[2] * w2];

      var alpha = color1.alpha * p + color2.alpha * (1 - p);

      return new Color(rgb, alpha);
    },
    greyscale: function (color) {
      return colorFunctions.desaturate(color, new Dimension(100));
    },
    contrast: function (color, dark, light, threshold) {
      // filter: contrast(3.2);
      // should be kept as is, so check for color
      if (!color.rgb) {
        return null;
      }
      if (typeof light === 'undefined') {
        light = colorFunctions.rgba(255, 255, 255, 1.0);
      }
      if (typeof dark === 'undefined') {
        dark = colorFunctions.rgba(0, 0, 0, 1.0);
      }
      //Figure out which is actually light and dark!
      if (dark.luma() > light.luma()) {
        var t = light;
        light = dark;
        dark = t;
      }
      if (typeof threshold === 'undefined') {
        threshold = 0.43;
      } else {
        threshold = number(threshold);
      }
      if (color.luma() < threshold) {
        return light;
      } else {
        return dark;
      }
    },
    argb: function (color) {
      return new Anonymous(color.toARGB());
    },
    color: function(c) {
      if ((c instanceof Quoted) &&
        (/^#([a-f0-9]{6}|[a-f0-9]{3})$/i.test(c.value))) {
        return new Color(c.value.slice(1));
      }
      if ((c instanceof Color) || (c = Color.fromKeyword(c.value))) {
        c.value = undefined;
        return c;
      }
      throw {
        type:    "Argument",
        message: "argument must be a color keyword or 3/6 digit hex e.g. #FFF"
      };
    },
    tint: function(color, amount) {
      return colorFunctions.mix(colorFunctions.rgb(255, 255, 255), color, amount);
    },
    shade: function(color, amount) {
      return colorFunctions.mix(colorFunctions.rgb(0, 0, 0), color, amount);
    }
  };
  functionRegistry.addMultiple(colorFunctions);

},{"../tree/anonymous":46,"../tree/color":50,"../tree/dimension":56,"../tree/quoted":73,"./function-registry":22}],19:[function(require,module,exports){
  module.exports = function(environment) {
    var Quoted = require("../tree/quoted"),
      URL = require("../tree/url"),
      functionRegistry = require("./function-registry"),
      fallback = function(functionThis, node) {
        return new URL(node, functionThis.index, functionThis.currentFileInfo).eval(functionThis.context);
      },
      logger = require('../logger');

    functionRegistry.add("data-uri", function(mimetypeNode, filePathNode) {

      if (!filePathNode) {
        filePathNode = mimetypeNode;
        mimetypeNode = null;
      }

      var mimetype = mimetypeNode && mimetypeNode.value;
      var filePath = filePathNode.value;
      var currentFileInfo = this.currentFileInfo;
      var currentDirectory = currentFileInfo.relativeUrls ?
        currentFileInfo.currentDirectory : currentFileInfo.entryPath;

      var fragmentStart = filePath.indexOf('#');
      var fragment = '';
      if (fragmentStart !== -1) {
        fragment = filePath.slice(fragmentStart);
        filePath = filePath.slice(0, fragmentStart);
      }

      var fileManager = environment.getFileManager(filePath, currentDirectory, this.context, environment, true);

      if (!fileManager) {
        return fallback(this, filePathNode);
      }

      var useBase64 = false;

      // detect the mimetype if not given
      if (!mimetypeNode) {

        mimetype = environment.mimeLookup(filePath);

        if (mimetype === "image/svg+xml") {
          useBase64 = false;
        } else {
          // use base 64 unless it's an ASCII or UTF-8 format
          var charset = environment.charsetLookup(mimetype);
          useBase64 = ['US-ASCII', 'UTF-8'].indexOf(charset) < 0;
        }
        if (useBase64) { mimetype += ';base64'; }
      }
      else {
        useBase64 = /;base64$/.test(mimetype);
      }

      var fileSync = fileManager.loadFileSync(filePath, currentDirectory, this.context, environment);
      if (!fileSync.contents) {
        logger.warn("Skipped data-uri embedding of " + filePath + " because file not found");
        return fallback(this, filePathNode || mimetypeNode);
      }
      var buf = fileSync.contents;
      if (useBase64 && !environment.encodeBase64) {
        return fallback(this, filePathNode);
      }

      buf = useBase64 ? environment.encodeBase64(buf) : encodeURIComponent(buf);

      var uri = "data:" + mimetype + ',' + buf + fragment;

      // IE8 cannot handle a data-uri larger than 32,768 characters. If this is exceeded
      // and the --ieCompat flag is enabled, return a normal url() instead.
      var DATA_URI_MAX = 32768;
      if (uri.length >= DATA_URI_MAX) {

        if (this.context.ieCompat !== false) {
          logger.warn("Skipped data-uri embedding of " + filePath + " because its size (" + uri.length +
            " characters) exceeds IE8-safe " + DATA_URI_MAX + " characters!");

          return fallback(this, filePathNode || mimetypeNode);
        }
      }

      return new URL(new Quoted('"' + uri + '"', uri, false, this.index, this.currentFileInfo), this.index, this.currentFileInfo);
    });
  };

},{"../logger":33,"../tree/quoted":73,"../tree/url":80,"./function-registry":22}],20:[function(require,module,exports){
  var Keyword = require("../tree/keyword"),
    functionRegistry = require("./function-registry");

  var defaultFunc = {
    eval: function () {
      var v = this.value_, e = this.error_;
      if (e) {
        throw e;
      }
      if (v != null) {
        return v ? Keyword.True : Keyword.False;
      }
    },
    value: function (v) {
      this.value_ = v;
    },
    error: function (e) {
      this.error_ = e;
    },
    reset: function () {
      this.value_ = this.error_ = null;
    }
  };

  functionRegistry.add("default", defaultFunc.eval.bind(defaultFunc));

  module.exports = defaultFunc;

},{"../tree/keyword":65,"./function-registry":22}],21:[function(require,module,exports){
  var Expression = require("../tree/expression");

  var functionCaller = function(name, context, index, currentFileInfo) {
    this.name = name.toLowerCase();
    this.index = index;
    this.context = context;
    this.currentFileInfo = currentFileInfo;

    this.func = context.frames[0].functionRegistry.get(this.name);
  };
  functionCaller.prototype.isValid = function() {
    return Boolean(this.func);
  };
  functionCaller.prototype.call = function(args) {

    // This code is terrible and should be replaced as per this issue...
    // https://github.com/less/less.js/issues/2477
    if (Array.isArray(args)) {
      args = args.filter(function (item) {
        if (item.type === "Comment") {
          return false;
        }
        return true;
      })
        .map(function(item) {
          if (item.type === "Expression") {
            var subNodes = item.value.filter(function (item) {
              if (item.type === "Comment") {
                return false;
              }
              return true;
            });
            if (subNodes.length === 1) {
              return subNodes[0];
            } else {
              return new Expression(subNodes);
            }
          }
          return item;
        });
    }

    return this.func.apply(this, args);
  };

  module.exports = functionCaller;

},{"../tree/expression":59}],22:[function(require,module,exports){
  function makeRegistry( base ) {
    return {
      _data: {},
      add: function(name, func) {
        // precautionary case conversion, as later querying of
        // the registry by function-caller uses lower case as well.
        name = name.toLowerCase();

        if (this._data.hasOwnProperty(name)) {
          //TODO warn
        }
        this._data[name] = func;
      },
      addMultiple: function(functions) {
        Object.keys(functions).forEach(
          function(name) {
            this.add(name, functions[name]);
          }.bind(this));
      },
      get: function(name) {
        return this._data[name] || ( base && base.get( name ));
      },
      inherit : function() {
        return makeRegistry( this );
      }
    };
  }

  module.exports = makeRegistry( null );
},{}],23:[function(require,module,exports){
  module.exports = function(environment) {
    var functions = {
      functionRegistry: require("./function-registry"),
      functionCaller: require("./function-caller")
    };

    //register functions
    require("./default");
    require("./color");
    require("./color-blending");
    require("./data-uri")(environment);
    require("./math");
    require("./number");
    require("./string");
    require("./svg")(environment);
    require("./types");

    return functions;
  };

},{"./color":18,"./color-blending":17,"./data-uri":19,"./default":20,"./function-caller":21,"./function-registry":22,"./math":25,"./number":26,"./string":27,"./svg":28,"./types":29}],24:[function(require,module,exports){
  var Dimension = require("../tree/dimension");

  var MathHelper = function() {
  };
  MathHelper._math = function (fn, unit, n) {
    if (!(n instanceof Dimension)) {
      throw { type: "Argument", message: "argument must be a number" };
    }
    if (unit == null) {
      unit = n.unit;
    } else {
      n = n.unify();
    }
    return new Dimension(fn(parseFloat(n.value)), unit);
  };
  module.exports = MathHelper;
},{"../tree/dimension":56}],25:[function(require,module,exports){
  var functionRegistry = require("./function-registry"),
    mathHelper = require("./math-helper.js");

  var mathFunctions = {
    // name,  unit
    ceil:  null,
    floor: null,
    sqrt:  null,
    abs:   null,
    tan:   "",
    sin:   "",
    cos:   "",
    atan:  "rad",
    asin:  "rad",
    acos:  "rad"
  };

  for (var f in mathFunctions) {
    if (mathFunctions.hasOwnProperty(f)) {
      mathFunctions[f] = mathHelper._math.bind(null, Math[f], mathFunctions[f]);
    }
  }

  mathFunctions.round = function (n, f) {
    var fraction = typeof f === "undefined" ? 0 : f.value;
    return mathHelper._math(function(num) { return num.toFixed(fraction); }, null, n);
  };

  functionRegistry.addMultiple(mathFunctions);

},{"./function-registry":22,"./math-helper.js":24}],26:[function(require,module,exports){
  var Dimension = require("../tree/dimension"),
    Anonymous = require("../tree/anonymous"),
    functionRegistry = require("./function-registry"),
    mathHelper = require("./math-helper.js");

  var minMax = function (isMin, args) {
    args = Array.prototype.slice.call(args);
    switch(args.length) {
      case 0: throw { type: "Argument", message: "one or more arguments required" };
    }
    var i, j, current, currentUnified, referenceUnified, unit, unitStatic, unitClone,
      order  = [], // elems only contains original argument values.
      values = {}; // key is the unit.toString() for unified Dimension values,
    // value is the index into the order array.
    for (i = 0; i < args.length; i++) {
      current = args[i];
      if (!(current instanceof Dimension)) {
        if (Array.isArray(args[i].value)) {
          Array.prototype.push.apply(args, Array.prototype.slice.call(args[i].value));
        }
        continue;
      }
      currentUnified = current.unit.toString() === "" && unitClone !== undefined ? new Dimension(current.value, unitClone).unify() : current.unify();
      unit = currentUnified.unit.toString() === "" && unitStatic !== undefined ? unitStatic : currentUnified.unit.toString();
      unitStatic = unit !== "" && unitStatic === undefined || unit !== "" && order[0].unify().unit.toString() === "" ? unit : unitStatic;
      unitClone = unit !== "" && unitClone === undefined ? current.unit.toString() : unitClone;
      j = values[""] !== undefined && unit !== "" && unit === unitStatic ? values[""] : values[unit];
      if (j === undefined) {
        if (unitStatic !== undefined && unit !== unitStatic) {
          throw{ type: "Argument", message: "incompatible types" };
        }
        values[unit] = order.length;
        order.push(current);
        continue;
      }
      referenceUnified = order[j].unit.toString() === "" && unitClone !== undefined ? new Dimension(order[j].value, unitClone).unify() : order[j].unify();
      if ( isMin && currentUnified.value < referenceUnified.value ||
        !isMin && currentUnified.value > referenceUnified.value) {
        order[j] = current;
      }
    }
    if (order.length == 1) {
      return order[0];
    }
    args = order.map(function (a) { return a.toCSS(this.context); }).join(this.context.compress ? "," : ", ");
    return new Anonymous((isMin ? "min" : "max") + "(" + args + ")");
  };
  functionRegistry.addMultiple({
    min: function () {
      return minMax(true, arguments);
    },
    max: function () {
      return minMax(false, arguments);
    },
    convert: function (val, unit) {
      return val.convertTo(unit.value);
    },
    pi: function () {
      return new Dimension(Math.PI);
    },
    mod: function(a, b) {
      return new Dimension(a.value % b.value, a.unit);
    },
    pow: function(x, y) {
      if (typeof x === "number" && typeof y === "number") {
        x = new Dimension(x);
        y = new Dimension(y);
      } else if (!(x instanceof Dimension) || !(y instanceof Dimension)) {
        throw { type: "Argument", message: "arguments must be numbers" };
      }

      return new Dimension(Math.pow(x.value, y.value), x.unit);
    },
    percentage: function (n) {
      var result = mathHelper._math(function(num) {
        return num * 100;
      }, '%', n);

      return result;
    }
  });

},{"../tree/anonymous":46,"../tree/dimension":56,"./function-registry":22,"./math-helper.js":24}],27:[function(require,module,exports){
  var Quoted = require("../tree/quoted"),
    Anonymous = require("../tree/anonymous"),
    JavaScript = require("../tree/javascript"),
    functionRegistry = require("./function-registry");

  functionRegistry.addMultiple({
    e: function (str) {
      return new Anonymous(str instanceof JavaScript ? str.evaluated : str.value);
    },
    escape: function (str) {
      return new Anonymous(
        encodeURI(str.value).replace(/=/g, "%3D").replace(/:/g, "%3A").replace(/#/g, "%23").replace(/;/g, "%3B")
          .replace(/\(/g, "%28").replace(/\)/g, "%29"));
    },
    replace: function (string, pattern, replacement, flags) {
      var result = string.value;
      replacement = (replacement.type === "Quoted") ?
        replacement.value : replacement.toCSS();
      result = result.replace(new RegExp(pattern.value, flags ? flags.value : ''), replacement);
      return new Quoted(string.quote || '', result, string.escaped);
    },
    '%': function (string /* arg, arg, ...*/) {
      var args = Array.prototype.slice.call(arguments, 1),
        result = string.value;

      for (var i = 0; i < args.length; i++) {
        /*jshint loopfunc:true */
        result = result.replace(/%[sda]/i, function(token) {
          var value = ((args[i].type === "Quoted") &&
            token.match(/s/i)) ? args[i].value : args[i].toCSS();
          return token.match(/[A-Z]$/) ? encodeURIComponent(value) : value;
        });
      }
      result = result.replace(/%%/g, '%');
      return new Quoted(string.quote || '', result, string.escaped);
    }
  });

},{"../tree/anonymous":46,"../tree/javascript":63,"../tree/quoted":73,"./function-registry":22}],28:[function(require,module,exports){
  module.exports = function(environment) {
    var Dimension = require("../tree/dimension"),
      Color = require("../tree/color"),
      Expression = require("../tree/expression"),
      Quoted = require("../tree/quoted"),
      URL = require("../tree/url"),
      functionRegistry = require("./function-registry");

    functionRegistry.add("svg-gradient", function(direction) {

      var stops,
        gradientDirectionSvg,
        gradientType = "linear",
        rectangleDimension = 'x="0" y="0" width="1" height="1"',
        renderEnv = {compress: false},
        returner,
        directionValue = direction.toCSS(renderEnv),
        i, color, position, positionValue, alpha;

      function throwArgumentDescriptor() {
        throw { type: "Argument",
          message: "svg-gradient expects direction, start_color [start_position], [color position,]...," +
          " end_color [end_position] or direction, color list" };
      }

      if (arguments.length == 2) {
        if (arguments[1].value.length < 2) {
          throwArgumentDescriptor();
        }
        stops = arguments[1].value;
      } else if (arguments.length < 3) {
        throwArgumentDescriptor();
      } else {
        stops = Array.prototype.slice.call(arguments, 1);
      }

      switch (directionValue) {
        case "to bottom":
          gradientDirectionSvg = 'x1="0%" y1="0%" x2="0%" y2="100%"';
          break;
        case "to right":
          gradientDirectionSvg = 'x1="0%" y1="0%" x2="100%" y2="0%"';
          break;
        case "to bottom right":
          gradientDirectionSvg = 'x1="0%" y1="0%" x2="100%" y2="100%"';
          break;
        case "to top right":
          gradientDirectionSvg = 'x1="0%" y1="100%" x2="100%" y2="0%"';
          break;
        case "ellipse":
        case "ellipse at center":
          gradientType = "radial";
          gradientDirectionSvg = 'cx="50%" cy="50%" r="75%"';
          rectangleDimension = 'x="-50" y="-50" width="101" height="101"';
          break;
        default:
          throw { type: "Argument", message: "svg-gradient direction must be 'to bottom', 'to right'," +
          " 'to bottom right', 'to top right' or 'ellipse at center'" };
      }
      returner = '<?xml version="1.0" ?>' +
        '<svg xmlns="http://www.w3.org/2000/svg" version="1.1" width="100%" height="100%" viewBox="0 0 1 1" preserveAspectRatio="none">' +
        '<' + gradientType + 'Gradient id="gradient" gradientUnits="userSpaceOnUse" ' + gradientDirectionSvg + '>';

      for (i = 0; i < stops.length; i+= 1) {
        if (stops[i] instanceof Expression) {
          color = stops[i].value[0];
          position = stops[i].value[1];
        } else {
          color = stops[i];
          position = undefined;
        }

        if (!(color instanceof Color) || (!((i === 0 || i + 1 === stops.length) && position === undefined) && !(position instanceof Dimension))) {
          throwArgumentDescriptor();
        }
        positionValue = position ? position.toCSS(renderEnv) : i === 0 ? "0%" : "100%";
        alpha = color.alpha;
        returner += '<stop offset="' + positionValue + '" stop-color="' + color.toRGB() + '"' + (alpha < 1 ? ' stop-opacity="' + alpha + '"' : '') + '/>';
      }
      returner += '</' + gradientType + 'Gradient>' +
        '<rect ' + rectangleDimension + ' fill="url(#gradient)" /></svg>';

      returner = encodeURIComponent(returner);

      returner = "data:image/svg+xml," + returner;
      return new URL(new Quoted("'" + returner + "'", returner, false, this.index, this.currentFileInfo), this.index, this.currentFileInfo);
    });
  };

},{"../tree/color":50,"../tree/dimension":56,"../tree/expression":59,"../tree/quoted":73,"../tree/url":80,"./function-registry":22}],29:[function(require,module,exports){
  var Keyword = require("../tree/keyword"),
    DetachedRuleset = require("../tree/detached-ruleset"),
    Dimension = require("../tree/dimension"),
    Color = require("../tree/color"),
    Quoted = require("../tree/quoted"),
    Anonymous = require("../tree/anonymous"),
    URL = require("../tree/url"),
    Operation = require("../tree/operation"),
    functionRegistry = require("./function-registry");

  var isa = function (n, Type) {
      return (n instanceof Type) ? Keyword.True : Keyword.False;
    },
    isunit = function (n, unit) {
      if (unit === undefined) {
        throw { type: "Argument", message: "missing the required second argument to isunit." };
      }
      unit = typeof unit.value === "string" ? unit.value : unit;
      if (typeof unit !== "string") {
        throw { type: "Argument", message: "Second argument to isunit should be a unit or a string." };
      }
      return (n instanceof Dimension) && n.unit.is(unit) ? Keyword.True : Keyword.False;
    },
    getItemsFromNode = function(node) {
      // handle non-array values as an array of length 1
      // return 'undefined' if index is invalid
      var items = Array.isArray(node.value) ?
        node.value : Array(node);

      return items;
    };
  functionRegistry.addMultiple({
    isruleset: function (n) {
      return isa(n, DetachedRuleset);
    },
    iscolor: function (n) {
      return isa(n, Color);
    },
    isnumber: function (n) {
      return isa(n, Dimension);
    },
    isstring: function (n) {
      return isa(n, Quoted);
    },
    iskeyword: function (n) {
      return isa(n, Keyword);
    },
    isurl: function (n) {
      return isa(n, URL);
    },
    ispixel: function (n) {
      return isunit(n, 'px');
    },
    ispercentage: function (n) {
      return isunit(n, '%');
    },
    isem: function (n) {
      return isunit(n, 'em');
    },
    isunit: isunit,
    unit: function (val, unit) {
      if (!(val instanceof Dimension)) {
        throw { type: "Argument",
          message: "the first argument to unit must be a number" +
          (val instanceof Operation ? ". Have you forgotten parenthesis?" : "") };
      }
      if (unit) {
        if (unit instanceof Keyword) {
          unit = unit.value;
        } else {
          unit = unit.toCSS();
        }
      } else {
        unit = "";
      }
      return new Dimension(val.value, unit);
    },
    "get-unit": function (n) {
      return new Anonymous(n.unit);
    },
    extract: function(values, index) {
      index = index.value - 1; // (1-based index)

      return getItemsFromNode(values)[index];
    },
    length: function(values) {
      return new Dimension(getItemsFromNode(values).length);
    }
  });

},{"../tree/anonymous":46,"../tree/color":50,"../tree/detached-ruleset":55,"../tree/dimension":56,"../tree/keyword":65,"../tree/operation":71,"../tree/quoted":73,"../tree/url":80,"./function-registry":22}],30:[function(require,module,exports){
  var contexts = require("./contexts"),
    Parser = require('./parser/parser'),
    FunctionImporter = require('./plugins/function-importer');

  module.exports = function(environment) {

    // FileInfo = {
    //  'relativeUrls' - option - whether to adjust URL's to be relative
    //  'filename' - full resolved filename of current file
    //  'rootpath' - path to append to normal URLs for this node
    //  'currentDirectory' - path to the current file, absolute
    //  'rootFilename' - filename of the base file
    //  'entryPath' - absolute path to the entry file
    //  'reference' - whether the file should not be output and only output parts that are referenced

    var ImportManager = function(context, rootFileInfo) {
      this.rootFilename = rootFileInfo.filename;
      this.paths = context.paths || [];  // Search paths, when importing
      this.contents = {};             // map - filename to contents of all the files
      this.contentsIgnoredChars = {}; // map - filename to lines at the beginning of each file to ignore
      this.mime = context.mime;
      this.error = null;
      this.context = context;
      // Deprecated? Unused outside of here, could be useful.
      this.queue = [];        // Files which haven't been imported yet
      this.files = {};        // Holds the imported parse trees.
    };
    /**
     * Add an import to be imported
     * @param path - the raw path
     * @param tryAppendLessExtension - whether to try appending the less extension (if the path has no extension)
     * @param currentFileInfo - the current file info (used for instance to work out relative paths)
     * @param importOptions - import options
     * @param callback - callback for when it is imported
     */
    ImportManager.prototype.push = function (path, tryAppendLessExtension, currentFileInfo, importOptions, callback) {
      var importManager = this;
      this.queue.push(path);

      var fileParsedFunc = function (e, root, fullPath) {
        importManager.queue.splice(importManager.queue.indexOf(path), 1); // Remove the path from the queue

        var importedEqualsRoot = fullPath === importManager.rootFilename;
        if (importOptions.optional && e) {
          callback(null, {rules:[]}, false, null);
        }
        else {
          importManager.files[fullPath] = root;
          if (e && !importManager.error) { importManager.error = e; }
          callback(e, root, importedEqualsRoot, fullPath);
        }
      };

      var newFileInfo = {
        relativeUrls: this.context.relativeUrls,
        entryPath: currentFileInfo.entryPath,
        rootpath: currentFileInfo.rootpath,
        rootFilename: currentFileInfo.rootFilename
      };

      var fileManager = environment.getFileManager(path, currentFileInfo.currentDirectory, this.context, environment);

      if (!fileManager) {
        fileParsedFunc({ message: "Could not find a file-manager for " + path });
        return;
      }

      if (tryAppendLessExtension) {
        path = fileManager.tryAppendExtension(path, importOptions.plugin ? ".js" : ".less");
      }

      var loadFileCallback = function(loadedFile) {
        var resolvedFilename = loadedFile.filename,
          contents = loadedFile.contents.replace(/^\uFEFF/, '');

        // Pass on an updated rootpath if path of imported file is relative and file
        // is in a (sub|sup) directory
        //
        // Examples:
        // - If path of imported file is 'module/nav/nav.less' and rootpath is 'less/',
        //   then rootpath should become 'less/module/nav/'
        // - If path of imported file is '../mixins.less' and rootpath is 'less/',
        //   then rootpath should become 'less/../'
        newFileInfo.currentDirectory = fileManager.getPath(resolvedFilename);
        if (newFileInfo.relativeUrls) {
          newFileInfo.rootpath = fileManager.join(
            (importManager.context.rootpath || ""),
            fileManager.pathDiff(newFileInfo.currentDirectory, newFileInfo.entryPath));

          if (!fileManager.isPathAbsolute(newFileInfo.rootpath) && fileManager.alwaysMakePathsAbsolute()) {
            newFileInfo.rootpath = fileManager.join(newFileInfo.entryPath, newFileInfo.rootpath);
          }
        }
        newFileInfo.filename = resolvedFilename;

        var newEnv = new contexts.Parse(importManager.context);

        newEnv.processImports = false;
        importManager.contents[resolvedFilename] = contents;

        if (currentFileInfo.reference || importOptions.reference) {
          newFileInfo.reference = true;
        }

        if (importOptions.plugin) {
          new FunctionImporter(newEnv, newFileInfo).eval(contents, function (e, root) {
            fileParsedFunc(e, root, resolvedFilename);
          });
        } else if (importOptions.inline) {
          fileParsedFunc(null, contents, resolvedFilename);
        } else {
          new Parser(newEnv, importManager, newFileInfo).parse(contents, function (e, root) {
            fileParsedFunc(e, root, resolvedFilename);
          });
        }
      };

      var promise = fileManager.loadFile(path, currentFileInfo.currentDirectory, this.context, environment,
        function(err, loadedFile) {
          if (err) {
            fileParsedFunc(err);
          } else {
            loadFileCallback(loadedFile);
          }
        });
      if (promise) {
        promise.then(loadFileCallback, fileParsedFunc);
      }
    };
    return ImportManager;
  };

},{"./contexts":11,"./parser/parser":38,"./plugins/function-importer":40}],31:[function(require,module,exports){
  module.exports = function(environment, fileManagers) {
    var SourceMapOutput, SourceMapBuilder, ParseTree, ImportManager, Environment;

    var less = {
      version: [2, 7, 3],
      data: require('./data'),
      tree: require('./tree'),
      Environment: (Environment = require("./environment/environment")),
      AbstractFileManager: require("./environment/abstract-file-manager"),
      environment: (environment = new Environment(environment, fileManagers)),
      visitors: require('./visitors'),
      Parser: require('./parser/parser'),
      functions: require('./functions')(environment),
      contexts: require("./contexts"),
      SourceMapOutput: (SourceMapOutput = require('./source-map-output')(environment)),
      SourceMapBuilder: (SourceMapBuilder = require('./source-map-builder')(SourceMapOutput, environment)),
      ParseTree: (ParseTree = require('./parse-tree')(SourceMapBuilder)),
      ImportManager: (ImportManager = require('./import-manager')(environment)),
      render: require("./render")(environment, ParseTree, ImportManager),
      parse: require("./parse")(environment, ParseTree, ImportManager),
      LessError: require('./less-error'),
      transformTree: require('./transform-tree'),
      utils: require('./utils'),
      PluginManager: require('./plugin-manager'),
      logger: require('./logger')
    };

    return less;
  };

},{"./contexts":11,"./data":13,"./environment/abstract-file-manager":15,"./environment/environment":16,"./functions":23,"./import-manager":30,"./less-error":32,"./logger":33,"./parse":35,"./parse-tree":34,"./parser/parser":38,"./plugin-manager":39,"./render":41,"./source-map-builder":42,"./source-map-output":43,"./transform-tree":44,"./tree":62,"./utils":83,"./visitors":87}],32:[function(require,module,exports){
  var utils = require("./utils");

  var LessError = module.exports = function LessError(e, importManager, currentFilename) {

    Error.call(this);

    var filename = e.filename || currentFilename;

    if (importManager && filename) {
      var input = importManager.contents[filename],
        loc = utils.getLocation(e.index, input),
        line = loc.line,
        col  = loc.column,
        callLine = e.call && utils.getLocation(e.call, input).line,
        lines = input.split('\n');

      this.type = e.type || 'Syntax';
      this.filename = filename;
      this.index = e.index;
      this.line = typeof line === 'number' ? line + 1 : null;
      this.callLine = callLine + 1;
      this.callExtract = lines[callLine];
      this.column = col;
      this.extract = [
        lines[line - 1],
        lines[line],
        lines[line + 1]
      ];
    }
    this.message = e.message;
    this.stack = e.stack;
  };

  if (typeof Object.create === 'undefined') {
    var F = function () {};
    F.prototype = Error.prototype;
    LessError.prototype = new F();
  } else {
    LessError.prototype = Object.create(Error.prototype);
  }

  LessError.prototype.constructor = LessError;

},{"./utils":83}],33:[function(require,module,exports){
  module.exports = {
    error: function(msg) {
      this._fireEvent("error", msg);
    },
    warn: function(msg) {
      this._fireEvent("warn", msg);
    },
    info: function(msg) {
      this._fireEvent("info", msg);
    },
    debug: function(msg) {
      this._fireEvent("debug", msg);
    },
    addListener: function(listener) {
      this._listeners.push(listener);
    },
    removeListener: function(listener) {
      for (var i = 0; i < this._listeners.length; i++) {
        if (this._listeners[i] === listener) {
          this._listeners.splice(i, 1);
          return;
        }
      }
    },
    _fireEvent: function(type, msg) {
      for (var i = 0; i < this._listeners.length; i++) {
        var logFunction = this._listeners[i][type];
        if (logFunction) {
          logFunction(msg);
        }
      }
    },
    _listeners: []
  };

},{}],34:[function(require,module,exports){
  var LessError = require('./less-error'),
    transformTree = require("./transform-tree"),
    logger = require("./logger");

  module.exports = function(SourceMapBuilder) {
    var ParseTree = function(root, imports) {
      this.root = root;
      this.imports = imports;
    };

    ParseTree.prototype.toCSS = function(options) {
      var evaldRoot, result = {}, sourceMapBuilder;
      try {
        evaldRoot = transformTree(this.root, options);
      } catch (e) {
        throw new LessError(e, this.imports);
      }

      try {
        var compress = Boolean(options.compress);
        if (compress) {
          logger.warn("The compress option has been deprecated. We recommend you use a dedicated css minifier, for instance see less-plugin-clean-css.");
        }

        var toCSSOptions = {
          compress: compress,
          dumpLineNumbers: options.dumpLineNumbers,
          strictUnits: Boolean(options.strictUnits),
          numPrecision: 8};

        if (options.sourceMap) {
          sourceMapBuilder = new SourceMapBuilder(options.sourceMap);
          result.css = sourceMapBuilder.toCSS(evaldRoot, toCSSOptions, this.imports);
        } else {
          result.css = evaldRoot.toCSS(toCSSOptions);
        }
      } catch (e) {
        throw new LessError(e, this.imports);
      }

      if (options.pluginManager) {
        var postProcessors = options.pluginManager.getPostProcessors();
        for (var i = 0; i < postProcessors.length; i++) {
          result.css = postProcessors[i].process(result.css, { sourceMap: sourceMapBuilder, options: options, imports: this.imports });
        }
      }
      if (options.sourceMap) {
        result.map = sourceMapBuilder.getExternalSourceMap();
      }

      result.imports = [];
      for (var file in this.imports.files) {
        if (this.imports.files.hasOwnProperty(file) && file !== this.imports.rootFilename) {
          result.imports.push(file);
        }
      }
      return result;
    };
    return ParseTree;
  };

},{"./less-error":32,"./logger":33,"./transform-tree":44}],35:[function(require,module,exports){
  var PromiseConstructor,
    contexts = require("./contexts"),
    Parser = require('./parser/parser'),
    PluginManager = require('./plugin-manager');

  module.exports = function(environment, ParseTree, ImportManager) {
    var parse = function (input, options, callback) {
      options = options || {};

      if (typeof options === 'function') {
        callback = options;
        options = {};
      }

      if (!callback) {
        if (!PromiseConstructor) {
          PromiseConstructor = typeof Promise === 'undefined' ? require('promise') : Promise;
        }
        var self = this;
        return new PromiseConstructor(function (resolve, reject) {
          parse.call(self, input, options, function(err, output) {
            if (err) {
              reject(err);
            } else {
              resolve(output);
            }
          });
        });
      } else {
        var context,
          rootFileInfo,
          pluginManager = new PluginManager(this);

        pluginManager.addPlugins(options.plugins);
        options.pluginManager = pluginManager;

        context = new contexts.Parse(options);

        if (options.rootFileInfo) {
          rootFileInfo = options.rootFileInfo;
        } else {
          var filename = options.filename || "input";
          var entryPath = filename.replace(/[^\/\\]*$/, "");
          rootFileInfo = {
            filename: filename,
            relativeUrls: context.relativeUrls,
            rootpath: context.rootpath || "",
            currentDirectory: entryPath,
            entryPath: entryPath,
            rootFilename: filename
          };
          // add in a missing trailing slash
          if (rootFileInfo.rootpath && rootFileInfo.rootpath.slice(-1) !== "/") {
            rootFileInfo.rootpath += "/";
          }
        }

        var imports = new ImportManager(context, rootFileInfo);

        new Parser(context, imports, rootFileInfo)
          .parse(input, function (e, root) {
            if (e) { return callback(e); }
            callback(null, root, imports, options);
          }, options);
      }
    };
    return parse;
  };

},{"./contexts":11,"./parser/parser":38,"./plugin-manager":39,"promise":undefined}],36:[function(require,module,exports){
// Split the input into chunks.
  module.exports = function (input, fail) {
    var len = input.length, level = 0, parenLevel = 0,
      lastOpening, lastOpeningParen, lastMultiComment, lastMultiCommentEndBrace,
      chunks = [], emitFrom = 0,
      chunkerCurrentIndex, currentChunkStartIndex, cc, cc2, matched;

    function emitChunk(force) {
      var len = chunkerCurrentIndex - emitFrom;
      if (((len < 512) && !force) || !len) {
        return;
      }
      chunks.push(input.slice(emitFrom, chunkerCurrentIndex + 1));
      emitFrom = chunkerCurrentIndex + 1;
    }

    for (chunkerCurrentIndex = 0; chunkerCurrentIndex < len; chunkerCurrentIndex++) {
      cc = input.charCodeAt(chunkerCurrentIndex);
      if (((cc >= 97) && (cc <= 122)) || (cc < 34)) {
        // a-z or whitespace
        continue;
      }

      switch (cc) {
        case 40:                        // (
          parenLevel++;
          lastOpeningParen = chunkerCurrentIndex;
          continue;
        case 41:                        // )
          if (--parenLevel < 0) {
            return fail("missing opening `(`", chunkerCurrentIndex);
          }
          continue;
        case 59:                        // ;
          if (!parenLevel) { emitChunk(); }
          continue;
        case 123:                       // {
          level++;
          lastOpening = chunkerCurrentIndex;
          continue;
        case 125:                       // }
          if (--level < 0) {
            return fail("missing opening `{`", chunkerCurrentIndex);
          }
          if (!level && !parenLevel) { emitChunk(); }
          continue;
        case 92:                        // \
          if (chunkerCurrentIndex < len - 1) { chunkerCurrentIndex++; continue; }
          return fail("unescaped `\\`", chunkerCurrentIndex);
        case 34:
        case 39:
        case 96:                        // ", ' and `
          matched = 0;
          currentChunkStartIndex = chunkerCurrentIndex;
          for (chunkerCurrentIndex = chunkerCurrentIndex + 1; chunkerCurrentIndex < len; chunkerCurrentIndex++) {
            cc2 = input.charCodeAt(chunkerCurrentIndex);
            if (cc2 > 96) { continue; }
            if (cc2 == cc) { matched = 1; break; }
            if (cc2 == 92) {        // \
              if (chunkerCurrentIndex == len - 1) {
                return fail("unescaped `\\`", chunkerCurrentIndex);
              }
              chunkerCurrentIndex++;
            }
          }
          if (matched) { continue; }
          return fail("unmatched `" + String.fromCharCode(cc) + "`", currentChunkStartIndex);
        case 47:                        // /, check for comment
          if (parenLevel || (chunkerCurrentIndex == len - 1)) { continue; }
          cc2 = input.charCodeAt(chunkerCurrentIndex + 1);
          if (cc2 == 47) {
            // //, find lnfeed
            for (chunkerCurrentIndex = chunkerCurrentIndex + 2; chunkerCurrentIndex < len; chunkerCurrentIndex++) {
              cc2 = input.charCodeAt(chunkerCurrentIndex);
              if ((cc2 <= 13) && ((cc2 == 10) || (cc2 == 13))) { break; }
            }
          } else if (cc2 == 42) {
            // /*, find */
            lastMultiComment = currentChunkStartIndex = chunkerCurrentIndex;
            for (chunkerCurrentIndex = chunkerCurrentIndex + 2; chunkerCurrentIndex < len - 1; chunkerCurrentIndex++) {
              cc2 = input.charCodeAt(chunkerCurrentIndex);
              if (cc2 == 125) { lastMultiCommentEndBrace = chunkerCurrentIndex; }
              if (cc2 != 42) { continue; }
              if (input.charCodeAt(chunkerCurrentIndex + 1) == 47) { break; }
            }
            if (chunkerCurrentIndex == len - 1) {
              return fail("missing closing `*/`", currentChunkStartIndex);
            }
            chunkerCurrentIndex++;
          }
          continue;
        case 42:                       // *, check for unmatched */
          if ((chunkerCurrentIndex < len - 1) && (input.charCodeAt(chunkerCurrentIndex + 1) == 47)) {
            return fail("unmatched `/*`", chunkerCurrentIndex);
          }
          continue;
      }
    }

    if (level !== 0) {
      if ((lastMultiComment > lastOpening) && (lastMultiCommentEndBrace > lastMultiComment)) {
        return fail("missing closing `}` or `*/`", lastOpening);
      } else {
        return fail("missing closing `}`", lastOpening);
      }
    } else if (parenLevel !== 0) {
      return fail("missing closing `)`", lastOpeningParen);
    }

    emitChunk(true);
    return chunks;
  };

},{}],37:[function(require,module,exports){
  var chunker = require('./chunker');

  module.exports = function() {
    var input,       // LeSS input string
      j,           // current chunk
      saveStack = [],   // holds state for backtracking
      furthest,    // furthest index the parser has gone to
      furthestPossibleErrorMessage,// if this is furthest we got to, this is the probably cause
      chunks,      // chunkified input
      current,     // current chunk
      currentPos,  // index of current chunk, in `input`
      parserInput = {};

    var CHARCODE_SPACE = 32,
      CHARCODE_TAB = 9,
      CHARCODE_LF = 10,
      CHARCODE_CR = 13,
      CHARCODE_PLUS = 43,
      CHARCODE_COMMA = 44,
      CHARCODE_FORWARD_SLASH = 47,
      CHARCODE_9 = 57;

    function skipWhitespace(length) {
      var oldi = parserInput.i, oldj = j,
        curr = parserInput.i - currentPos,
        endIndex = parserInput.i + current.length - curr,
        mem = (parserInput.i += length),
        inp = input,
        c, nextChar, comment;

      for (; parserInput.i < endIndex; parserInput.i++) {
        c = inp.charCodeAt(parserInput.i);

        if (parserInput.autoCommentAbsorb && c === CHARCODE_FORWARD_SLASH) {
          nextChar = inp.charAt(parserInput.i + 1);
          if (nextChar === '/') {
            comment = {index: parserInput.i, isLineComment: true};
            var nextNewLine = inp.indexOf("\n", parserInput.i + 2);
            if (nextNewLine < 0) {
              nextNewLine = endIndex;
            }
            parserInput.i = nextNewLine;
            comment.text = inp.substr(comment.index, parserInput.i - comment.index);
            parserInput.commentStore.push(comment);
            continue;
          } else if (nextChar === '*') {
            var nextStarSlash = inp.indexOf("*/", parserInput.i + 2);
            if (nextStarSlash >= 0) {
              comment = {
                index: parserInput.i,
                text: inp.substr(parserInput.i, nextStarSlash + 2 - parserInput.i),
                isLineComment: false
              };
              parserInput.i += comment.text.length - 1;
              parserInput.commentStore.push(comment);
              continue;
            }
          }
          break;
        }

        if ((c !== CHARCODE_SPACE) && (c !== CHARCODE_LF) && (c !== CHARCODE_TAB) && (c !== CHARCODE_CR)) {
          break;
        }
      }

      current = current.slice(length + parserInput.i - mem + curr);
      currentPos = parserInput.i;

      if (!current.length) {
        if (j < chunks.length - 1) {
          current = chunks[++j];
          skipWhitespace(0); // skip space at the beginning of a chunk
          return true; // things changed
        }
        parserInput.finished = true;
      }

      return oldi !== parserInput.i || oldj !== j;
    }

    parserInput.save = function() {
      currentPos = parserInput.i;
      saveStack.push( { current: current, i: parserInput.i, j: j });
    };
    parserInput.restore = function(possibleErrorMessage) {

      if (parserInput.i > furthest || (parserInput.i === furthest && possibleErrorMessage && !furthestPossibleErrorMessage)) {
        furthest = parserInput.i;
        furthestPossibleErrorMessage = possibleErrorMessage;
      }
      var state = saveStack.pop();
      current = state.current;
      currentPos = parserInput.i = state.i;
      j = state.j;
    };
    parserInput.forget = function() {
      saveStack.pop();
    };
    parserInput.isWhitespace = function (offset) {
      var pos = parserInput.i + (offset || 0),
        code = input.charCodeAt(pos);
      return (code === CHARCODE_SPACE || code === CHARCODE_CR || code === CHARCODE_TAB || code === CHARCODE_LF);
    };

    // Specialization of $(tok)
    parserInput.$re = function(tok) {
      if (parserInput.i > currentPos) {
        current = current.slice(parserInput.i - currentPos);
        currentPos = parserInput.i;
      }

      var m = tok.exec(current);
      if (!m) {
        return null;
      }

      skipWhitespace(m[0].length);
      if (typeof m === "string") {
        return m;
      }

      return m.length === 1 ? m[0] : m;
    };

    parserInput.$char = function(tok) {
      if (input.charAt(parserInput.i) !== tok) {
        return null;
      }
      skipWhitespace(1);
      return tok;
    };

    parserInput.$str = function(tok) {
      var tokLength = tok.length;

      // https://jsperf.com/string-startswith/21
      for (var i = 0; i < tokLength; i++) {
        if (input.charAt(parserInput.i + i) !== tok.charAt(i)) {
          return null;
        }
      }

      skipWhitespace(tokLength);
      return tok;
    };

    parserInput.$quoted = function() {

      var startChar = input.charAt(parserInput.i);
      if (startChar !== "'" && startChar !== '"') {
        return;
      }
      var length = input.length,
        currentPosition = parserInput.i;

      for (var i = 1; i + currentPosition < length; i++) {
        var nextChar = input.charAt(i + currentPosition);
        switch(nextChar) {
          case "\\":
            i++;
            continue;
          case "\r":
          case "\n":
            break;
          case startChar:
            var str = input.substr(currentPosition, i + 1);
            skipWhitespace(i + 1);
            return str;
          default:
        }
      }
      return null;
    };

    parserInput.autoCommentAbsorb = true;
    parserInput.commentStore = [];
    parserInput.finished = false;

    // Same as $(), but don't change the state of the parser,
    // just return the match.
    parserInput.peek = function(tok) {
      if (typeof tok === 'string') {
        // https://jsperf.com/string-startswith/21
        for (var i = 0; i < tok.length; i++) {
          if (input.charAt(parserInput.i + i) !== tok.charAt(i)) {
            return false;
          }
        }
        return true;
      } else {
        return tok.test(current);
      }
    };

    // Specialization of peek()
    // TODO remove or change some currentChar calls to peekChar
    parserInput.peekChar = function(tok) {
      return input.charAt(parserInput.i) === tok;
    };

    parserInput.currentChar = function() {
      return input.charAt(parserInput.i);
    };

    parserInput.getInput = function() {
      return input;
    };

    parserInput.peekNotNumeric = function() {
      var c = input.charCodeAt(parserInput.i);
      //Is the first char of the dimension 0-9, '.', '+' or '-'
      return (c > CHARCODE_9 || c < CHARCODE_PLUS) || c === CHARCODE_FORWARD_SLASH || c === CHARCODE_COMMA;
    };

    parserInput.start = function(str, chunkInput, failFunction) {
      input = str;
      parserInput.i = j = currentPos = furthest = 0;

      // chunking apparently makes things quicker (but my tests indicate
      // it might actually make things slower in node at least)
      // and it is a non-perfect parse - it can't recognise
      // unquoted urls, meaning it can't distinguish comments
      // meaning comments with quotes or {}() in them get 'counted'
      // and then lead to parse errors.
      // In addition if the chunking chunks in the wrong place we might
      // not be able to parse a parser statement in one go
      // this is officially deprecated but can be switched on via an option
      // in the case it causes too much performance issues.
      if (chunkInput) {
        chunks = chunker(str, failFunction);
      } else {
        chunks = [str];
      }

      current = chunks[0];

      skipWhitespace(0);
    };

    parserInput.end = function() {
      var message,
        isFinished = parserInput.i >= input.length;

      if (parserInput.i < furthest) {
        message = furthestPossibleErrorMessage;
        parserInput.i = furthest;
      }
      return {
        isFinished: isFinished,
        furthest: parserInput.i,
        furthestPossibleErrorMessage: message,
        furthestReachedEnd: parserInput.i >= input.length - 1,
        furthestChar: input[parserInput.i]
      };
    };

    return parserInput;
  };

},{"./chunker":36}],38:[function(require,module,exports){
  var LessError = require('../less-error'),
    tree = require("../tree"),
    visitors = require("../visitors"),
    getParserInput = require("./parser-input"),
    utils = require("../utils");

//
// less.js - parser
//
//    A relatively straight-forward predictive parser.
//    There is no tokenization/lexing stage, the input is parsed
//    in one sweep.
//
//    To make the parser fast enough to run in the browser, several
//    optimization had to be made:
//
//    - Matching and slicing on a huge input is often cause of slowdowns.
//      The solution is to chunkify the input into smaller strings.
//      The chunks are stored in the `chunks` var,
//      `j` holds the current chunk index, and `currentPos` holds
//      the index of the current chunk in relation to `input`.
//      This gives us an almost 4x speed-up.
//
//    - In many cases, we don't need to match individual tokens;
//      for example, if a value doesn't hold any variables, operations
//      or dynamic references, the parser can effectively 'skip' it,
//      treating it as a literal.
//      An example would be '1px solid #000' - which evaluates to itself,
//      we don't need to know what the individual components are.
//      The drawback, of course is that you don't get the benefits of
//      syntax-checking on the CSS. This gives us a 50% speed-up in the parser,
//      and a smaller speed-up in the code-gen.
//
//
//    Token matching is done with the `$` function, which either takes
//    a terminal string or regexp, or a non-terminal function to call.
//    It also takes care of moving all the indices forwards.
//`
//
  var Parser = function Parser(context, imports, fileInfo) {
    var parsers,
      parserInput = getParserInput();

    function error(msg, type) {
      throw new LessError(
        {
          index: parserInput.i,
          filename: fileInfo.filename,
          type: type || 'Syntax',
          message: msg
        },
        imports
      );
    }

    function expect(arg, msg, index) {
      // some older browsers return typeof 'function' for RegExp
      var result = (arg instanceof Function) ? arg.call(parsers) : parserInput.$re(arg);
      if (result) {
        return result;
      }
      error(msg || (typeof arg === 'string' ? "expected '" + arg + "' got '" + parserInput.currentChar() + "'"
        : "unexpected token"));
    }

    // Specialization of expect()
    function expectChar(arg, msg) {
      if (parserInput.$char(arg)) {
        return arg;
      }
      error(msg || "expected '" + arg + "' got '" + parserInput.currentChar() + "'");
    }

    function getDebugInfo(index) {
      var filename = fileInfo.filename;

      return {
        lineNumber: utils.getLocation(index, parserInput.getInput()).line + 1,
        fileName: filename
      };
    }

    //
    // The Parser
    //
    return {

      //
      // Parse an input string into an abstract syntax tree,
      // @param str A string containing 'less' markup
      // @param callback call `callback` when done.
      // @param [additionalData] An optional map which can contains vars - a map (key, value) of variables to apply
      //
      parse: function (str, callback, additionalData) {
        var root, error = null, globalVars, modifyVars, ignored, preText = "";

        globalVars = (additionalData && additionalData.globalVars) ? Parser.serializeVars(additionalData.globalVars) + '\n' : '';
        modifyVars = (additionalData && additionalData.modifyVars) ? '\n' + Parser.serializeVars(additionalData.modifyVars) : '';

        if (context.pluginManager) {
          var preProcessors = context.pluginManager.getPreProcessors();
          for (var i = 0; i < preProcessors.length; i++) {
            str = preProcessors[i].process(str, { context: context, imports: imports, fileInfo: fileInfo });
          }
        }

        if (globalVars || (additionalData && additionalData.banner)) {
          preText = ((additionalData && additionalData.banner) ? additionalData.banner : "") + globalVars;
          ignored = imports.contentsIgnoredChars;
          ignored[fileInfo.filename] = ignored[fileInfo.filename] || 0;
          ignored[fileInfo.filename] += preText.length;
        }

        str = str.replace(/\r\n?/g, '\n');
        // Remove potential UTF Byte Order Mark
        str = preText + str.replace(/^\uFEFF/, '') + modifyVars;
        imports.contents[fileInfo.filename] = str;

        // Start with the primary rule.
        // The whole syntax tree is held under a Ruleset node,
        // with the `root` property set to true, so no `{}` are
        // output. The callback is called when the input is parsed.
        try {
          parserInput.start(str, context.chunkInput, function fail(msg, index) {
            throw new LessError({
              index: index,
              type: 'Parse',
              message: msg,
              filename: fileInfo.filename
            }, imports);
          });

          root = new(tree.Ruleset)(null, this.parsers.primary());
          root.root = true;
          root.firstRoot = true;
        } catch (e) {
          return callback(new LessError(e, imports, fileInfo.filename));
        }

        // If `i` is smaller than the `input.length - 1`,
        // it means the parser wasn't able to parse the whole
        // string, so we've got a parsing error.
        //
        // We try to extract a \n delimited string,
        // showing the line where the parse error occurred.
        // We split it up into two parts (the part which parsed,
        // and the part which didn't), so we can color them differently.
        var endInfo = parserInput.end();
        if (!endInfo.isFinished) {

          var message = endInfo.furthestPossibleErrorMessage;

          if (!message) {
            message = "Unrecognised input";
            if (endInfo.furthestChar === '}') {
              message += ". Possibly missing opening '{'";
            } else if (endInfo.furthestChar === ')') {
              message += ". Possibly missing opening '('";
            } else if (endInfo.furthestReachedEnd) {
              message += ". Possibly missing something";
            }
          }

          error = new LessError({
            type: "Parse",
            message: message,
            index: endInfo.furthest,
            filename: fileInfo.filename
          }, imports);
        }

        var finish = function (e) {
          e = error || e || imports.error;

          if (e) {
            if (!(e instanceof LessError)) {
              e = new LessError(e, imports, fileInfo.filename);
            }

            return callback(e);
          }
          else {
            return callback(null, root);
          }
        };

        if (context.processImports !== false) {
          new visitors.ImportVisitor(imports, finish)
            .run(root);
        } else {
          return finish();
        }
      },

      //
      // Here in, the parsing rules/functions
      //
      // The basic structure of the syntax tree generated is as follows:
      //
      //   Ruleset ->  Rule -> Value -> Expression -> Entity
      //
      // Here's some Less code:
      //
      //    .class {
      //      color: #fff;
      //      border: 1px solid #000;
      //      width: @w + 4px;
      //      > .child {...}
      //    }
      //
      // And here's what the parse tree might look like:
      //
      //     Ruleset (Selector '.class', [
      //         Rule ("color",  Value ([Expression [Color #fff]]))
      //         Rule ("border", Value ([Expression [Dimension 1px][Keyword "solid"][Color #000]]))
      //         Rule ("width",  Value ([Expression [Operation " + " [Variable "@w"][Dimension 4px]]]))
      //         Ruleset (Selector [Element '>', '.child'], [...])
      //     ])
      //
      //  In general, most rules will try to parse a token with the `$re()` function, and if the return
      //  value is truly, will return a new node, of the relevant type. Sometimes, we need to check
      //  first, before parsing, that's when we use `peek()`.
      //
      parsers: parsers = {
        //
        // The `primary` rule is the *entry* and *exit* point of the parser.
        // The rules here can appear at any level of the parse tree.
        //
        // The recursive nature of the grammar is an interplay between the `block`
        // rule, which represents `{ ... }`, the `ruleset` rule, and this `primary` rule,
        // as represented by this simplified grammar:
        //
        //     primary  →  (ruleset | rule)+
        //     ruleset  →  selector+ block
        //     block    →  '{' primary '}'
        //
        // Only at one point is the primary rule not called from the
        // block rule: at the root level.
        //
        primary: function () {
          var mixin = this.mixin, root = [], node;

          while (true) {
            while (true) {
              node = this.comment();
              if (!node) { break; }
              root.push(node);
            }
            // always process comments before deciding if finished
            if (parserInput.finished) {
              break;
            }
            if (parserInput.peek('}')) {
              break;
            }

            node = this.extendRule();
            if (node) {
              root = root.concat(node);
              continue;
            }

            node = mixin.definition() || this.rule() || this.ruleset() ||
              mixin.call() || this.rulesetCall() || this.entities.call() || this.directive();
            if (node) {
              root.push(node);
            } else {
              var foundSemiColon = false;
              while (parserInput.$char(";")) {
                foundSemiColon = true;
              }
              if (!foundSemiColon) {
                break;
              }
            }
          }

          return root;
        },

        // comments are collected by the main parsing mechanism and then assigned to nodes
        // where the current structure allows it
        comment: function () {
          if (parserInput.commentStore.length) {
            var comment = parserInput.commentStore.shift();
            return new(tree.Comment)(comment.text, comment.isLineComment, comment.index, fileInfo);
          }
        },

        //
        // Entities are tokens which can be found inside an Expression
        //
        entities: {
          //
          // A string, which supports escaping " and '
          //
          //     "milky way" 'he\'s the one!'
          //
          quoted: function () {
            var str, index = parserInput.i, isEscaped = false;

            parserInput.save();
            if (parserInput.$char("~")) {
              isEscaped = true;
            }
            str = parserInput.$quoted();
            if (!str) {
              parserInput.restore();
              return;
            }
            parserInput.forget();

            return new(tree.Quoted)(str.charAt(0), str.substr(1, str.length - 2), isEscaped, index, fileInfo);
          },

          //
          // A catch-all word, such as:
          //
          //     black border-collapse
          //
          keyword: function () {
            var k = parserInput.$char("%") || parserInput.$re(/^[_A-Za-z-][_A-Za-z0-9-]*/);
            if (k) {
              return tree.Color.fromKeyword(k) || new(tree.Keyword)(k);
            }
          },

          //
          // A function call
          //
          //     rgb(255, 0, 255)
          //
          // We also try to catch IE's `alpha()`, but let the `alpha` parser
          // deal with the details.
          //
          // The arguments are parsed with the `entities.arguments` parser.
          //
          call: function () {
            var name, nameLC, args, alpha, index = parserInput.i;

            // http://jsperf.com/case-insensitive-regex-vs-strtolower-then-regex/18
            if (parserInput.peek(/^url\(/i)) {
              return;
            }

            parserInput.save();

            name = parserInput.$re(/^([\w-]+|%|progid:[\w\.]+)\(/);
            if (!name) { parserInput.forget(); return; }

            name = name[1];
            nameLC = name.toLowerCase();

            if (nameLC === 'alpha') {
              alpha = parsers.alpha();
              if (alpha) {
                parserInput.forget();
                return alpha;
              }
            }

            args = this.arguments();

            if (! parserInput.$char(')')) {
              parserInput.restore("Could not parse call arguments or missing ')'");
              return;
            }

            parserInput.forget();
            return new(tree.Call)(name, args, index, fileInfo);
          },
          arguments: function () {
            var argsSemiColon = [], argsComma = [],
              expressions = [],
              isSemiColonSeparated, value, arg;

            parserInput.save();

            while (true) {

              arg = parsers.detachedRuleset() || this.assignment() || parsers.expression();

              if (!arg) {
                break;
              }

              value = arg;

              if (arg.value && arg.value.length == 1) {
                value = arg.value[0];
              }

              if (value) {
                expressions.push(value);
              }

              argsComma.push(value);

              if (parserInput.$char(',')) {
                continue;
              }

              if (parserInput.$char(';') || isSemiColonSeparated) {

                isSemiColonSeparated = true;

                if (expressions.length > 1) {
                  value = new(tree.Value)(expressions);
                }
                argsSemiColon.push(value);

                expressions = [];
              }
            }

            parserInput.forget();
            return isSemiColonSeparated ? argsSemiColon : argsComma;
          },
          literal: function () {
            return this.dimension() ||
              this.color() ||
              this.quoted() ||
              this.unicodeDescriptor();
          },

          // Assignments are argument entities for calls.
          // They are present in ie filter properties as shown below.
          //
          //     filter: progid:DXImageTransform.Microsoft.Alpha( *opacity=50* )
          //

          assignment: function () {
            var key, value;
            parserInput.save();
            key = parserInput.$re(/^\w+(?=\s?=)/i);
            if (!key) {
              parserInput.restore();
              return;
            }
            if (!parserInput.$char('=')) {
              parserInput.restore();
              return;
            }
            value = parsers.entity();
            if (value) {
              parserInput.forget();
              return new(tree.Assignment)(key, value);
            } else {
              parserInput.restore();
            }
          },

          //
          // Parse url() tokens
          //
          // We use a specific rule for urls, because they don't really behave like
          // standard function calls. The difference is that the argument doesn't have
          // to be enclosed within a string, so it can't be parsed as an Expression.
          //
          url: function () {
            var value, index = parserInput.i;

            parserInput.autoCommentAbsorb = false;

            if (!parserInput.$str("url(")) {
              parserInput.autoCommentAbsorb = true;
              return;
            }

            value = this.quoted() || this.variable() ||
              parserInput.$re(/^(?:(?:\\[\(\)'"])|[^\(\)'"])+/) || "";

            parserInput.autoCommentAbsorb = true;

            expectChar(')');

            return new(tree.URL)((value.value != null || value instanceof tree.Variable) ?
              value : new(tree.Anonymous)(value), index, fileInfo);
          },

          //
          // A Variable entity, such as `@fink`, in
          //
          //     width: @fink + 2px
          //
          // We use a different parser for variable definitions,
          // see `parsers.variable`.
          //
          variable: function () {
            var name, index = parserInput.i;

            if (parserInput.currentChar() === '@' && (name = parserInput.$re(/^@@?[\w-]+/))) {
              return new(tree.Variable)(name, index, fileInfo);
            }
          },

          // A variable entity using the protective {} e.g. @{var}
          variableCurly: function () {
            var curly, index = parserInput.i;

            if (parserInput.currentChar() === '@' && (curly = parserInput.$re(/^@\{([\w-]+)\}/))) {
              return new(tree.Variable)("@" + curly[1], index, fileInfo);
            }
          },

          //
          // A Hexadecimal color
          //
          //     #4F3C2F
          //
          // `rgb` and `hsl` colors are parsed through the `entities.call` parser.
          //
          color: function () {
            var rgb;

            if (parserInput.currentChar() === '#' && (rgb = parserInput.$re(/^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})/))) {
              // strip colons, brackets, whitespaces and other characters that should not
              // definitely be part of color string
              var colorCandidateString = rgb.input.match(/^#([\w]+).*/);
              colorCandidateString = colorCandidateString[1];
              if (!colorCandidateString.match(/^[A-Fa-f0-9]+$/)) { // verify if candidate consists only of allowed HEX characters
                error("Invalid HEX color code");
              }
              return new(tree.Color)(rgb[1], undefined, '#' + colorCandidateString);
            }
          },

          colorKeyword: function () {
            parserInput.save();
            var autoCommentAbsorb = parserInput.autoCommentAbsorb;
            parserInput.autoCommentAbsorb = false;
            var k = parserInput.$re(/^[_A-Za-z-][_A-Za-z0-9-]+/);
            parserInput.autoCommentAbsorb = autoCommentAbsorb;
            if (!k) {
              parserInput.forget();
              return;
            }
            parserInput.restore();
            var color = tree.Color.fromKeyword(k);
            if (color) {
              parserInput.$str(k);
              return color;
            }
          },

          //
          // A Dimension, that is, a number and a unit
          //
          //     0.5em 95%
          //
          dimension: function () {
            if (parserInput.peekNotNumeric()) {
              return;
            }

            var value = parserInput.$re(/^([+-]?\d*\.?\d+)(%|[a-z_]+)?/i);
            if (value) {
              return new(tree.Dimension)(value[1], value[2]);
            }
          },

          //
          // A unicode descriptor, as is used in unicode-range
          //
          // U+0??  or U+00A1-00A9
          //
          unicodeDescriptor: function () {
            var ud;

            ud = parserInput.$re(/^U\+[0-9a-fA-F?]+(\-[0-9a-fA-F?]+)?/);
            if (ud) {
              return new(tree.UnicodeDescriptor)(ud[0]);
            }
          },

          //
          // JavaScript code to be evaluated
          //
          //     `window.location.href`
          //
          javascript: function () {
            var js, index = parserInput.i;

            parserInput.save();

            var escape = parserInput.$char("~");
            var jsQuote = parserInput.$char("`");

            if (!jsQuote) {
              parserInput.restore();
              return;
            }

            js = parserInput.$re(/^[^`]*`/);
            if (js) {
              parserInput.forget();
              return new(tree.JavaScript)(js.substr(0, js.length - 1), Boolean(escape), index, fileInfo);
            }
            parserInput.restore("invalid javascript definition");
          }
        },

        //
        // The variable part of a variable definition. Used in the `rule` parser
        //
        //     @fink:
        //
        variable: function () {
          var name;

          if (parserInput.currentChar() === '@' && (name = parserInput.$re(/^(@[\w-]+)\s*:/))) { return name[1]; }
        },

        //
        // The variable part of a variable definition. Used in the `rule` parser
        //
        //     @fink();
        //
        rulesetCall: function () {
          var name;

          if (parserInput.currentChar() === '@' && (name = parserInput.$re(/^(@[\w-]+)\(\s*\)\s*;/))) {
            return new tree.RulesetCall(name[1]);
          }
        },

        //
        // extend syntax - used to extend selectors
        //
        extend: function(isRule) {
          var elements, e, index = parserInput.i, option, extendList, extend;

          if (!parserInput.$str(isRule ? "&:extend(" : ":extend(")) {
            return;
          }

          do {
            option = null;
            elements = null;
            while (! (option = parserInput.$re(/^(all)(?=\s*(\)|,))/))) {
              e = this.element();
              if (!e) {
                break;
              }
              if (elements) {
                elements.push(e);
              } else {
                elements = [ e ];
              }
            }

            option = option && option[1];
            if (!elements) {
              error("Missing target selector for :extend().");
            }
            extend = new(tree.Extend)(new(tree.Selector)(elements), option, index, fileInfo);
            if (extendList) {
              extendList.push(extend);
            } else {
              extendList = [ extend ];
            }
          } while (parserInput.$char(","));

          expect(/^\)/);

          if (isRule) {
            expect(/^;/);
          }

          return extendList;
        },

        //
        // extendRule - used in a rule to extend all the parent selectors
        //
        extendRule: function() {
          return this.extend(true);
        },

        //
        // Mixins
        //
        mixin: {
          //
          // A Mixin call, with an optional argument list
          //
          //     #mixins > .square(#fff);
          //     .rounded(4px, black);
          //     .button;
          //
          // The `while` loop is there because mixins can be
          // namespaced, but we only support the child and descendant
          // selector for now.
          //
          call: function () {
            var s = parserInput.currentChar(), important = false, index = parserInput.i, elemIndex,
              elements, elem, e, c, args;

            if (s !== '.' && s !== '#') { return; }

            parserInput.save(); // stop us absorbing part of an invalid selector

            while (true) {
              elemIndex = parserInput.i;
              e = parserInput.$re(/^[#.](?:[\w-]|\\(?:[A-Fa-f0-9]{1,6} ?|[^A-Fa-f0-9]))+/);
              if (!e) {
                break;
              }
              elem = new(tree.Element)(c, e, elemIndex, fileInfo);
              if (elements) {
                elements.push(elem);
              } else {
                elements = [ elem ];
              }
              c = parserInput.$char('>');
            }

            if (elements) {
              if (parserInput.$char('(')) {
                args = this.args(true).args;
                expectChar(')');
              }

              if (parsers.important()) {
                important = true;
              }

              if (parsers.end()) {
                parserInput.forget();
                return new(tree.mixin.Call)(elements, args, index, fileInfo, important);
              }
            }

            parserInput.restore();
          },
          args: function (isCall) {
            var entities = parsers.entities,
              returner = { args:null, variadic: false },
              expressions = [], argsSemiColon = [], argsComma = [],
              isSemiColonSeparated, expressionContainsNamed, name, nameLoop,
              value, arg, expand;

            parserInput.save();

            while (true) {
              if (isCall) {
                arg = parsers.detachedRuleset() || parsers.expression();
              } else {
                parserInput.commentStore.length = 0;
                if (parserInput.$str("...")) {
                  returner.variadic = true;
                  if (parserInput.$char(";") && !isSemiColonSeparated) {
                    isSemiColonSeparated = true;
                  }
                  (isSemiColonSeparated ? argsSemiColon : argsComma)
                    .push({ variadic: true });
                  break;
                }
                arg = entities.variable() || entities.literal() || entities.keyword();
              }

              if (!arg) {
                break;
              }

              nameLoop = null;
              if (arg.throwAwayComments) {
                arg.throwAwayComments();
              }
              value = arg;
              var val = null;

              if (isCall) {
                // Variable
                if (arg.value && arg.value.length == 1) {
                  val = arg.value[0];
                }
              } else {
                val = arg;
              }

              if (val && val instanceof tree.Variable) {
                if (parserInput.$char(':')) {
                  if (expressions.length > 0) {
                    if (isSemiColonSeparated) {
                      error("Cannot mix ; and , as delimiter types");
                    }
                    expressionContainsNamed = true;
                  }

                  value = parsers.detachedRuleset() || parsers.expression();

                  if (!value) {
                    if (isCall) {
                      error("could not understand value for named argument");
                    } else {
                      parserInput.restore();
                      returner.args = [];
                      return returner;
                    }
                  }
                  nameLoop = (name = val.name);
                } else if (parserInput.$str("...")) {
                  if (!isCall) {
                    returner.variadic = true;
                    if (parserInput.$char(";") && !isSemiColonSeparated) {
                      isSemiColonSeparated = true;
                    }
                    (isSemiColonSeparated ? argsSemiColon : argsComma)
                      .push({ name: arg.name, variadic: true });
                    break;
                  } else {
                    expand = true;
                  }
                } else if (!isCall) {
                  name = nameLoop = val.name;
                  value = null;
                }
              }

              if (value) {
                expressions.push(value);
              }

              argsComma.push({ name:nameLoop, value:value, expand:expand });

              if (parserInput.$char(',')) {
                continue;
              }

              if (parserInput.$char(';') || isSemiColonSeparated) {

                if (expressionContainsNamed) {
                  error("Cannot mix ; and , as delimiter types");
                }

                isSemiColonSeparated = true;

                if (expressions.length > 1) {
                  value = new(tree.Value)(expressions);
                }
                argsSemiColon.push({ name:name, value:value, expand:expand });

                name = null;
                expressions = [];
                expressionContainsNamed = false;
              }
            }

            parserInput.forget();
            returner.args = isSemiColonSeparated ? argsSemiColon : argsComma;
            return returner;
          },
          //
          // A Mixin definition, with a list of parameters
          //
          //     .rounded (@radius: 2px, @color) {
          //        ...
          //     }
          //
          // Until we have a finer grained state-machine, we have to
          // do a look-ahead, to make sure we don't have a mixin call.
          // See the `rule` function for more information.
          //
          // We start by matching `.rounded (`, and then proceed on to
          // the argument list, which has optional default values.
          // We store the parameters in `params`, with a `value` key,
          // if there is a value, such as in the case of `@radius`.
          //
          // Once we've got our params list, and a closing `)`, we parse
          // the `{...}` block.
          //
          definition: function () {
            var name, params = [], match, ruleset, cond, variadic = false;
            if ((parserInput.currentChar() !== '.' && parserInput.currentChar() !== '#') ||
              parserInput.peek(/^[^{]*\}/)) {
              return;
            }

            parserInput.save();

            match = parserInput.$re(/^([#.](?:[\w-]|\\(?:[A-Fa-f0-9]{1,6} ?|[^A-Fa-f0-9]))+)\s*\(/);
            if (match) {
              name = match[1];

              var argInfo = this.args(false);
              params = argInfo.args;
              variadic = argInfo.variadic;

              // .mixincall("@{a}");
              // looks a bit like a mixin definition..
              // also
              // .mixincall(@a: {rule: set;});
              // so we have to be nice and restore
              if (!parserInput.$char(')')) {
                parserInput.restore("Missing closing ')'");
                return;
              }

              parserInput.commentStore.length = 0;

              if (parserInput.$str("when")) { // Guard
                cond = expect(parsers.conditions, 'expected condition');
              }

              ruleset = parsers.block();

              if (ruleset) {
                parserInput.forget();
                return new(tree.mixin.Definition)(name, params, ruleset, cond, variadic);
              } else {
                parserInput.restore();
              }
            } else {
              parserInput.forget();
            }
          }
        },

        //
        // Entities are the smallest recognized token,
        // and can be found inside a rule's value.
        //
        entity: function () {
          var entities = this.entities;

          return this.comment() || entities.literal() || entities.variable() || entities.url() ||
            entities.call()    || entities.keyword()  || entities.javascript();
        },

        //
        // A Rule terminator. Note that we use `peek()` to check for '}',
        // because the `block` rule will be expecting it, but we still need to make sure
        // it's there, if ';' was omitted.
        //
        end: function () {
          return parserInput.$char(';') || parserInput.peek('}');
        },

        //
        // IE's alpha function
        //
        //     alpha(opacity=88)
        //
        alpha: function () {
          var value;

          // http://jsperf.com/case-insensitive-regex-vs-strtolower-then-regex/18
          if (! parserInput.$re(/^opacity=/i)) { return; }
          value = parserInput.$re(/^\d+/);
          if (!value) {
            value = expect(this.entities.variable, "Could not parse alpha");
          }
          expectChar(')');
          return new(tree.Alpha)(value);
        },

        //
        // A Selector Element
        //
        //     div
        //     + h1
        //     #socks
        //     input[type="text"]
        //
        // Elements are the building blocks for Selectors,
        // they are made out of a `Combinator` (see combinator rule),
        // and an element name, such as a tag a class, or `*`.
        //
        element: function () {
          var e, c, v, index = parserInput.i;

          c = this.combinator();

          e = parserInput.$re(/^(?:\d+\.\d+|\d+)%/) ||
            parserInput.$re(/^(?:[.#]?|:*)(?:[\w-]|[^\x00-\x9f]|\\(?:[A-Fa-f0-9]{1,6} ?|[^A-Fa-f0-9]))+/) ||
            parserInput.$char('*') || parserInput.$char('&') || this.attribute() ||
            parserInput.$re(/^\([^&()@]+\)/) ||  parserInput.$re(/^[\.#:](?=@)/) ||
            this.entities.variableCurly();

          if (! e) {
            parserInput.save();
            if (parserInput.$char('(')) {
              if ((v = this.selector()) && parserInput.$char(')')) {
                e = new(tree.Paren)(v);
                parserInput.forget();
              } else {
                parserInput.restore("Missing closing ')'");
              }
            } else {
              parserInput.forget();
            }
          }

          if (e) { return new(tree.Element)(c, e, index, fileInfo); }
        },

        //
        // Combinators combine elements together, in a Selector.
        //
        // Because our parser isn't white-space sensitive, special care
        // has to be taken, when parsing the descendant combinator, ` `,
        // as it's an empty space. We have to check the previous character
        // in the input, to see if it's a ` ` character. More info on how
        // we deal with this in *combinator.js*.
        //
        combinator: function () {
          var c = parserInput.currentChar();

          if (c === '/') {
            parserInput.save();
            var slashedCombinator = parserInput.$re(/^\/[a-z]+\//i);
            if (slashedCombinator) {
              parserInput.forget();
              return new(tree.Combinator)(slashedCombinator);
            }
            parserInput.restore();
          }

          if (c === '>' || c === '+' || c === '~' || c === '|' || c === '^') {
            parserInput.i++;
            if (c === '^' && parserInput.currentChar() === '^') {
              c = '^^';
              parserInput.i++;
            }
            while (parserInput.isWhitespace()) { parserInput.i++; }
            return new(tree.Combinator)(c);
          } else if (parserInput.isWhitespace(-1)) {
            return new(tree.Combinator)(" ");
          } else {
            return new(tree.Combinator)(null);
          }
        },
        //
        // A CSS selector (see selector below)
        // with less extensions e.g. the ability to extend and guard
        //
        lessSelector: function () {
          return this.selector(true);
        },
        //
        // A CSS Selector
        //
        //     .class > div + h1
        //     li a:hover
        //
        // Selectors are made out of one or more Elements, see above.
        //
        selector: function (isLess) {
          var index = parserInput.i, elements, extendList, c, e, allExtends, when, condition;

          while ((isLess && (extendList = this.extend())) || (isLess && (when = parserInput.$str("when"))) || (e = this.element())) {
            if (when) {
              condition = expect(this.conditions, 'expected condition');
            } else if (condition) {
              error("CSS guard can only be used at the end of selector");
            } else if (extendList) {
              if (allExtends) {
                allExtends = allExtends.concat(extendList);
              } else {
                allExtends = extendList;
              }
            } else {
              if (allExtends) { error("Extend can only be used at the end of selector"); }
              c = parserInput.currentChar();
              if (elements) {
                elements.push(e);
              } else {
                elements = [ e ];
              }
              e = null;
            }
            if (c === '{' || c === '}' || c === ';' || c === ',' || c === ')') {
              break;
            }
          }

          if (elements) { return new(tree.Selector)(elements, allExtends, condition, index, fileInfo); }
          if (allExtends) { error("Extend must be used to extend a selector, it cannot be used on its own"); }
        },
        attribute: function () {
          if (! parserInput.$char('[')) { return; }

          var entities = this.entities,
            key, val, op;

          if (!(key = entities.variableCurly())) {
            key = expect(/^(?:[_A-Za-z0-9-\*]*\|)?(?:[_A-Za-z0-9-]|\\.)+/);
          }

          op = parserInput.$re(/^[|~*$^]?=/);
          if (op) {
            val = entities.quoted() || parserInput.$re(/^[0-9]+%/) || parserInput.$re(/^[\w-]+/) || entities.variableCurly();
          }

          expectChar(']');

          return new(tree.Attribute)(key, op, val);
        },

        //
        // The `block` rule is used by `ruleset` and `mixin.definition`.
        // It's a wrapper around the `primary` rule, with added `{}`.
        //
        block: function () {
          var content;
          if (parserInput.$char('{') && (content = this.primary()) && parserInput.$char('}')) {
            return content;
          }
        },

        blockRuleset: function() {
          var block = this.block();

          if (block) {
            block = new tree.Ruleset(null, block);
          }
          return block;
        },

        detachedRuleset: function() {
          var blockRuleset = this.blockRuleset();
          if (blockRuleset) {
            return new tree.DetachedRuleset(blockRuleset);
          }
        },

        //
        // div, .class, body > p {...}
        //
        ruleset: function () {
          var selectors, s, rules, debugInfo;

          parserInput.save();

          if (context.dumpLineNumbers) {
            debugInfo = getDebugInfo(parserInput.i);
          }

          while (true) {
            s = this.lessSelector();
            if (!s) {
              break;
            }
            if (selectors) {
              selectors.push(s);
            } else {
              selectors = [ s ];
            }
            parserInput.commentStore.length = 0;
            if (s.condition && selectors.length > 1) {
              error("Guards are only currently allowed on a single selector.");
            }
            if (! parserInput.$char(',')) { break; }
            if (s.condition) {
              error("Guards are only currently allowed on a single selector.");
            }
            parserInput.commentStore.length = 0;
          }

          if (selectors && (rules = this.block())) {
            parserInput.forget();
            var ruleset = new(tree.Ruleset)(selectors, rules, context.strictImports);
            if (context.dumpLineNumbers) {
              ruleset.debugInfo = debugInfo;
            }
            return ruleset;
          } else {
            parserInput.restore();
          }
        },
        rule: function (tryAnonymous) {
          var name, value, startOfRule = parserInput.i, c = parserInput.currentChar(), important, merge, isVariable;

          if (c === '.' || c === '#' || c === '&' || c === ':') { return; }

          parserInput.save();

          name = this.variable() || this.ruleProperty();
          if (name) {
            isVariable = typeof name === "string";

            if (isVariable) {
              value = this.detachedRuleset();
            }

            parserInput.commentStore.length = 0;
            if (!value) {
              // a name returned by this.ruleProperty() is always an array of the form:
              // [string-1, ..., string-n, ""] or [string-1, ..., string-n, "+"]
              // where each item is a tree.Keyword or tree.Variable
              merge = !isVariable && name.length > 1 && name.pop().value;

              // prefer to try to parse first if its a variable or we are compressing
              // but always fallback on the other one
              var tryValueFirst = !tryAnonymous && (context.compress || isVariable);

              if (tryValueFirst) {
                value = this.value();
              }
              if (!value) {
                value = this.anonymousValue();
                if (value) {
                  parserInput.forget();
                  // anonymous values absorb the end ';' which is required for them to work
                  return new (tree.Rule)(name, value, false, merge, startOfRule, fileInfo);
                }
              }
              if (!tryValueFirst && !value) {
                value = this.value();
              }

              important = this.important();
            }

            if (value && this.end()) {
              parserInput.forget();
              return new (tree.Rule)(name, value, important, merge, startOfRule, fileInfo);
            } else {
              parserInput.restore();
              if (value && !tryAnonymous) {
                return this.rule(true);
              }
            }
          } else {
            parserInput.forget();
          }
        },
        anonymousValue: function () {
          var match = parserInput.$re(/^([^@+\/'"*`(;{}-]*);/);
          if (match) {
            return new(tree.Anonymous)(match[1]);
          }
        },

        //
        // An @import directive
        //
        //     @import "lib";
        //
        // Depending on our environment, importing is done differently:
        // In the browser, it's an XHR request, in Node, it would be a
        // file-system operation. The function used for importing is
        // stored in `import`, which we pass to the Import constructor.
        //
        "import": function () {
          var path, features, index = parserInput.i;

          var dir = parserInput.$re(/^@import?\s+/);

          if (dir) {
            var options = (dir ? this.importOptions() : null) || {};

            if ((path = this.entities.quoted() || this.entities.url())) {
              features = this.mediaFeatures();

              if (!parserInput.$char(';')) {
                parserInput.i = index;
                error("missing semi-colon or unrecognised media features on import");
              }
              features = features && new(tree.Value)(features);
              return new(tree.Import)(path, features, options, index, fileInfo);
            }
            else {
              parserInput.i = index;
              error("malformed import statement");
            }
          }
        },

        importOptions: function() {
          var o, options = {}, optionName, value;

          // list of options, surrounded by parens
          if (! parserInput.$char('(')) { return null; }
          do {
            o = this.importOption();
            if (o) {
              optionName = o;
              value = true;
              switch(optionName) {
                case "css":
                  optionName = "less";
                  value = false;
                  break;
                case "once":
                  optionName = "multiple";
                  value = false;
                  break;
              }
              options[optionName] = value;
              if (! parserInput.$char(',')) { break; }
            }
          } while (o);
          expectChar(')');
          return options;
        },

        importOption: function() {
          var opt = parserInput.$re(/^(less|css|multiple|once|inline|reference|optional)/);
          if (opt) {
            return opt[1];
          }
        },

        mediaFeature: function () {
          var entities = this.entities, nodes = [], e, p;
          parserInput.save();
          do {
            e = entities.keyword() || entities.variable();
            if (e) {
              nodes.push(e);
            } else if (parserInput.$char('(')) {
              p = this.property();
              e = this.value();
              if (parserInput.$char(')')) {
                if (p && e) {
                  nodes.push(new(tree.Paren)(new(tree.Rule)(p, e, null, null, parserInput.i, fileInfo, true)));
                } else if (e) {
                  nodes.push(new(tree.Paren)(e));
                } else {
                  error("badly formed media feature definition");
                }
              } else {
                error("Missing closing ')'", "Parse");
              }
            }
          } while (e);

          parserInput.forget();
          if (nodes.length > 0) {
            return new(tree.Expression)(nodes);
          }
        },

        mediaFeatures: function () {
          var entities = this.entities, features = [], e;
          do {
            e = this.mediaFeature();
            if (e) {
              features.push(e);
              if (! parserInput.$char(',')) { break; }
            } else {
              e = entities.variable();
              if (e) {
                features.push(e);
                if (! parserInput.$char(',')) { break; }
              }
            }
          } while (e);

          return features.length > 0 ? features : null;
        },

        media: function () {
          var features, rules, media, debugInfo, index = parserInput.i;

          if (context.dumpLineNumbers) {
            debugInfo = getDebugInfo(index);
          }

          parserInput.save();

          if (parserInput.$str("@media")) {
            features = this.mediaFeatures();

            rules = this.block();

            if (!rules) {
              error("media definitions require block statements after any features");
            }

            parserInput.forget();

            media = new(tree.Media)(rules, features, index, fileInfo);
            if (context.dumpLineNumbers) {
              media.debugInfo = debugInfo;
            }

            return media;
          }

          parserInput.restore();
        },

        //
        // A @plugin directive, used to import compiler extensions dynamically.
        //
        //     @plugin "lib";
        //
        // Depending on our environment, importing is done differently:
        // In the browser, it's an XHR request, in Node, it would be a
        // file-system operation. The function used for importing is
        // stored in `import`, which we pass to the Import constructor.
        //
        plugin: function () {
          var path,
            index = parserInput.i,
            dir   = parserInput.$re(/^@plugin?\s+/);

          if (dir) {
            var options = { plugin : true };

            if ((path = this.entities.quoted() || this.entities.url())) {

              if (!parserInput.$char(';')) {
                parserInput.i = index;
                error("missing semi-colon on plugin");
              }

              return new(tree.Import)(path, null, options, index, fileInfo);
            }
            else {
              parserInput.i = index;
              error("malformed plugin statement");
            }
          }
        },

        //
        // A CSS Directive
        //
        //     @charset "utf-8";
        //
        directive: function () {
          var index = parserInput.i, name, value, rules, nonVendorSpecificName,
            hasIdentifier, hasExpression, hasUnknown, hasBlock = true, isRooted = true;

          if (parserInput.currentChar() !== '@') { return; }

          value = this['import']() || this.plugin() || this.media();
          if (value) {
            return value;
          }

          parserInput.save();

          name = parserInput.$re(/^@[a-z-]+/);

          if (!name) { return; }

          nonVendorSpecificName = name;
          if (name.charAt(1) == '-' && name.indexOf('-', 2) > 0) {
            nonVendorSpecificName = "@" + name.slice(name.indexOf('-', 2) + 1);
          }

          switch(nonVendorSpecificName) {
            case "@charset":
              hasIdentifier = true;
              hasBlock = false;
              break;
            case "@namespace":
              hasExpression = true;
              hasBlock = false;
              break;
            case "@keyframes":
            case "@counter-style":
              hasIdentifier = true;
              break;
            case "@document":
            case "@supports":
              hasUnknown = true;
              isRooted = false;
              break;
            default:
              hasUnknown = true;
              break;
          }

          parserInput.commentStore.length = 0;

          if (hasIdentifier) {
            value = this.entity();
            if (!value) {
              error("expected " + name + " identifier");
            }
          } else if (hasExpression) {
            value = this.expression();
            if (!value) {
              error("expected " + name + " expression");
            }
          } else if (hasUnknown) {
            value = (parserInput.$re(/^[^{;]+/) || '').trim();
            hasBlock = (parserInput.currentChar() == '{');
            if (value) {
              value = new(tree.Anonymous)(value);
            }
          }

          if (hasBlock) {
            rules = this.blockRuleset();
          }

          if (rules || (!hasBlock && value && parserInput.$char(';'))) {
            parserInput.forget();
            return new (tree.Directive)(name, value, rules, index, fileInfo,
              context.dumpLineNumbers ? getDebugInfo(index) : null,
              isRooted
            );
          }

          parserInput.restore("directive options not recognised");
        },

        //
        // A Value is a comma-delimited list of Expressions
        //
        //     font-family: Baskerville, Georgia, serif;
        //
        // In a Rule, a Value represents everything after the `:`,
        // and before the `;`.
        //
        value: function () {
          var e, expressions = [];

          do {
            e = this.expression();
            if (e) {
              expressions.push(e);
              if (! parserInput.$char(',')) { break; }
            }
          } while (e);

          if (expressions.length > 0) {
            return new(tree.Value)(expressions);
          }
        },
        important: function () {
          if (parserInput.currentChar() === '!') {
            return parserInput.$re(/^! *important/);
          }
        },
        sub: function () {
          var a, e;

          parserInput.save();
          if (parserInput.$char('(')) {
            a = this.addition();
            if (a && parserInput.$char(')')) {
              parserInput.forget();
              e = new(tree.Expression)([a]);
              e.parens = true;
              return e;
            }
            parserInput.restore("Expected ')'");
            return;
          }
          parserInput.restore();
        },
        multiplication: function () {
          var m, a, op, operation, isSpaced;
          m = this.operand();
          if (m) {
            isSpaced = parserInput.isWhitespace(-1);
            while (true) {
              if (parserInput.peek(/^\/[*\/]/)) {
                break;
              }

              parserInput.save();

              op = parserInput.$char('/') || parserInput.$char('*');

              if (!op) { parserInput.forget(); break; }

              a = this.operand();

              if (!a) { parserInput.restore(); break; }
              parserInput.forget();

              m.parensInOp = true;
              a.parensInOp = true;
              operation = new(tree.Operation)(op, [operation || m, a], isSpaced);
              isSpaced = parserInput.isWhitespace(-1);
            }
            return operation || m;
          }
        },
        addition: function () {
          var m, a, op, operation, isSpaced;
          m = this.multiplication();
          if (m) {
            isSpaced = parserInput.isWhitespace(-1);
            while (true) {
              op = parserInput.$re(/^[-+]\s+/) || (!isSpaced && (parserInput.$char('+') || parserInput.$char('-')));
              if (!op) {
                break;
              }
              a = this.multiplication();
              if (!a) {
                break;
              }

              m.parensInOp = true;
              a.parensInOp = true;
              operation = new(tree.Operation)(op, [operation || m, a], isSpaced);
              isSpaced = parserInput.isWhitespace(-1);
            }
            return operation || m;
          }
        },
        conditions: function () {
          var a, b, index = parserInput.i, condition;

          a = this.condition();
          if (a) {
            while (true) {
              if (!parserInput.peek(/^,\s*(not\s*)?\(/) || !parserInput.$char(',')) {
                break;
              }
              b = this.condition();
              if (!b) {
                break;
              }
              condition = new(tree.Condition)('or', condition || a, b, index);
            }
            return condition || a;
          }
        },
        condition: function () {
          var result, logical, next;
          function or() {
            return parserInput.$str("or");
          }

          result = this.conditionAnd(this);
          if (!result) {
            return ;
          }
          logical = or();
          if (logical) {
            next = this.condition();
            if (next) {
              result = new(tree.Condition)(logical, result, next);
            } else {
              return ;
            }
          }
          return result;
        },
        conditionAnd: function () {
          var result, logical, next;
          function insideCondition(me) {
            return me.negatedCondition() || me.parenthesisCondition();
          }
          function and() {
            return parserInput.$str("and");
          }

          result = insideCondition(this);
          if (!result) {
            return ;
          }
          logical = and();
          if (logical) {
            next = this.conditionAnd();
            if (next) {
              result = new(tree.Condition)(logical, result, next);
            } else {
              return ;
            }
          }
          return result;
        },
        negatedCondition: function () {
          if (parserInput.$str("not")) {
            var result = this.parenthesisCondition();
            if (result) {
              result.negate = !result.negate;
            }
            return result;
          }
        },
        parenthesisCondition: function () {
          function tryConditionFollowedByParenthesis(me) {
            var body;
            parserInput.save();
            body = me.condition();
            if (!body) {
              parserInput.restore();
              return ;
            }
            if (!parserInput.$char(')')) {
              parserInput.restore();
              return ;
            }
            parserInput.forget();
            return body;
          }

          var body;
          parserInput.save();
          if (!parserInput.$str("(")) {
            parserInput.restore();
            return ;
          }
          body = tryConditionFollowedByParenthesis(this);
          if (body) {
            parserInput.forget();
            return body;
          }

          body = this.atomicCondition();
          if (!body) {
            parserInput.restore();
            return ;
          }
          if (!parserInput.$char(')')) {
            parserInput.restore("expected ')' got '" + parserInput.currentChar() + "'");
            return ;
          }
          parserInput.forget();
          return body;
        },
        atomicCondition: function () {
          var entities = this.entities, index = parserInput.i, a, b, c, op;

          a = this.addition() || entities.keyword() || entities.quoted();
          if (a) {
            if (parserInput.$char('>')) {
              if (parserInput.$char('=')) {
                op = ">=";
              } else {
                op = '>';
              }
            } else
            if (parserInput.$char('<')) {
              if (parserInput.$char('=')) {
                op = "<=";
              } else {
                op = '<';
              }
            } else
            if (parserInput.$char('=')) {
              if (parserInput.$char('>')) {
                op = "=>";
              } else if (parserInput.$char('<')) {
                op = '=<';
              } else {
                op = '=';
              }
            }
            if (op) {
              b = this.addition() || entities.keyword() || entities.quoted();
              if (b) {
                c = new(tree.Condition)(op, a, b, index, false);
              } else {
                error('expected expression');
              }
            } else {
              c = new(tree.Condition)('=', a, new(tree.Keyword)('true'), index, false);
            }
            return c;
          }
        },

        //
        // An operand is anything that can be part of an operation,
        // such as a Color, or a Variable
        //
        operand: function () {
          var entities = this.entities, negate;

          if (parserInput.peek(/^-[@\(]/)) {
            negate = parserInput.$char('-');
          }

          var o = this.sub() || entities.dimension() ||
            entities.color() || entities.variable() ||
            entities.call() || entities.colorKeyword();

          if (negate) {
            o.parensInOp = true;
            o = new(tree.Negative)(o);
          }

          return o;
        },

        //
        // Expressions either represent mathematical operations,
        // or white-space delimited Entities.
        //
        //     1px solid black
        //     @var * 2
        //
        expression: function () {
          var entities = [], e, delim;

          do {
            e = this.comment();
            if (e) {
              entities.push(e);
              continue;
            }
            e = this.addition() || this.entity();
            if (e) {
              entities.push(e);
              // operations do not allow keyword "/" dimension (e.g. small/20px) so we support that here
              if (!parserInput.peek(/^\/[\/*]/)) {
                delim = parserInput.$char('/');
                if (delim) {
                  entities.push(new(tree.Anonymous)(delim));
                }
              }
            }
          } while (e);
          if (entities.length > 0) {
            return new(tree.Expression)(entities);
          }
        },
        property: function () {
          var name = parserInput.$re(/^(\*?-?[_a-zA-Z0-9-]+)\s*:/);
          if (name) {
            return name[1];
          }
        },
        ruleProperty: function () {
          var name = [], index = [], s, k;

          parserInput.save();

          var simpleProperty = parserInput.$re(/^([_a-zA-Z0-9-]+)\s*:/);
          if (simpleProperty) {
            name = [new(tree.Keyword)(simpleProperty[1])];
            parserInput.forget();
            return name;
          }

          function match(re) {
            var i = parserInput.i,
              chunk = parserInput.$re(re);
            if (chunk) {
              index.push(i);
              return name.push(chunk[1]);
            }
          }

          match(/^(\*?)/);
          while (true) {
            if (!match(/^((?:[\w-]+)|(?:@\{[\w-]+\}))/)) {
              break;
            }
          }

          if ((name.length > 1) && match(/^((?:\+_|\+)?)\s*:/)) {
            parserInput.forget();

            // at last, we have the complete match now. move forward,
            // convert name particles to tree objects and return:
            if (name[0] === '') {
              name.shift();
              index.shift();
            }
            for (k = 0; k < name.length; k++) {
              s = name[k];
              name[k] = (s.charAt(0) !== '@') ?
                new(tree.Keyword)(s) :
                new(tree.Variable)('@' + s.slice(2, -1),
                  index[k], fileInfo);
            }
            return name;
          }
          parserInput.restore();
        }
      }
    };
  };
  Parser.serializeVars = function(vars) {
    var s = '';

    for (var name in vars) {
      if (Object.hasOwnProperty.call(vars, name)) {
        var value = vars[name];
        s += ((name[0] === '@') ? '' : '@') + name + ': ' + value +
          ((String(value).slice(-1) === ';') ? '' : ';');
      }
    }

    return s;
  };

  module.exports = Parser;

},{"../less-error":32,"../tree":62,"../utils":83,"../visitors":87,"./parser-input":37}],39:[function(require,module,exports){
  /**
   * Plugin Manager
   */
  var PluginManager = function(less) {
    this.less = less;
    this.visitors = [];
    this.preProcessors = [];
    this.postProcessors = [];
    this.installedPlugins = [];
    this.fileManagers = [];
  };
  /**
   * Adds all the plugins in the array
   * @param {Array} plugins
   */
  PluginManager.prototype.addPlugins = function(plugins) {
    if (plugins) {
      for (var i = 0; i < plugins.length; i++) {
        this.addPlugin(plugins[i]);
      }
    }
  };
  /**
   *
   * @param plugin
   */
  PluginManager.prototype.addPlugin = function(plugin) {
    this.installedPlugins.push(plugin);
    plugin.install(this.less, this);
  };
  /**
   * Adds a visitor. The visitor object has options on itself to determine
   * when it should run.
   * @param visitor
   */
  PluginManager.prototype.addVisitor = function(visitor) {
    this.visitors.push(visitor);
  };
  /**
   * Adds a pre processor object
   * @param {object} preProcessor
   * @param {number} priority - guidelines 1 = before import, 1000 = import, 2000 = after import
   */
  PluginManager.prototype.addPreProcessor = function(preProcessor, priority) {
    var indexToInsertAt;
    for (indexToInsertAt = 0; indexToInsertAt < this.preProcessors.length; indexToInsertAt++) {
      if (this.preProcessors[indexToInsertAt].priority >= priority) {
        break;
      }
    }
    this.preProcessors.splice(indexToInsertAt, 0, {preProcessor: preProcessor, priority: priority});
  };
  /**
   * Adds a post processor object
   * @param {object} postProcessor
   * @param {number} priority - guidelines 1 = before compression, 1000 = compression, 2000 = after compression
   */
  PluginManager.prototype.addPostProcessor = function(postProcessor, priority) {
    var indexToInsertAt;
    for (indexToInsertAt = 0; indexToInsertAt < this.postProcessors.length; indexToInsertAt++) {
      if (this.postProcessors[indexToInsertAt].priority >= priority) {
        break;
      }
    }
    this.postProcessors.splice(indexToInsertAt, 0, {postProcessor: postProcessor, priority: priority});
  };
  /**
   *
   * @param manager
   */
  PluginManager.prototype.addFileManager = function(manager) {
    this.fileManagers.push(manager);
  };
  /**
   *
   * @returns {Array}
   * @private
   */
  PluginManager.prototype.getPreProcessors = function() {
    var preProcessors = [];
    for (var i = 0; i < this.preProcessors.length; i++) {
      preProcessors.push(this.preProcessors[i].preProcessor);
    }
    return preProcessors;
  };
  /**
   *
   * @returns {Array}
   * @private
   */
  PluginManager.prototype.getPostProcessors = function() {
    var postProcessors = [];
    for (var i = 0; i < this.postProcessors.length; i++) {
      postProcessors.push(this.postProcessors[i].postProcessor);
    }
    return postProcessors;
  };
  /**
   *
   * @returns {Array}
   * @private
   */
  PluginManager.prototype.getVisitors = function() {
    return this.visitors;
  };
  /**
   *
   * @returns {Array}
   * @private
   */
  PluginManager.prototype.getFileManagers = function() {
    return this.fileManagers;
  };
  module.exports = PluginManager;

},{}],40:[function(require,module,exports){
  var LessError = require('../less-error'),
    tree = require("../tree");

  var FunctionImporter = module.exports = function FunctionImporter(context, fileInfo) {
    this.fileInfo = fileInfo;
  };

  FunctionImporter.prototype.eval = function(contents, callback) {
    var loaded = {},
      loader,
      registry;

    registry = {
      add: function(name, func) {
        loaded[name] = func;
      },
      addMultiple: function(functions) {
        Object.keys(functions).forEach(function(name) {
          loaded[name] = functions[name];
        });
      }
    };

    try {
      loader = new Function("functions", "tree", "fileInfo", contents);
      loader(registry, tree, this.fileInfo);
    } catch(e) {
      callback(new LessError({
        message: "Plugin evaluation error: '" + e.name + ': ' + e.message.replace(/["]/g, "'") + "'" ,
        filename: this.fileInfo.filename
      }), null );
    }

    callback(null, { functions: loaded });
  };

},{"../less-error":32,"../tree":62}],41:[function(require,module,exports){
  var PromiseConstructor;

  module.exports = function(environment, ParseTree, ImportManager) {
    var render = function (input, options, callback) {
      if (typeof options === 'function') {
        callback = options;
        options = {};
      }

      if (!callback) {
        if (!PromiseConstructor) {
          PromiseConstructor = typeof Promise === 'undefined' ? require('promise') : Promise;
        }
        var self = this;
        return new PromiseConstructor(function (resolve, reject) {
          render.call(self, input, options, function(err, output) {
            if (err) {
              reject(err);
            } else {
              resolve(output);
            }
          });
        });
      } else {
        this.parse(input, options, function(err, root, imports, options) {
          if (err) { return callback(err); }

          var result;
          try {
            var parseTree = new ParseTree(root, imports);
            result = parseTree.toCSS(options);
          }
          catch (err) { return callback(err); }

          callback(null, result);
        });
      }
    };

    return render;
  };

},{"promise":undefined}],42:[function(require,module,exports){
  module.exports = function (SourceMapOutput, environment) {

    var SourceMapBuilder = function (options) {
      this.options = options;
    };

    SourceMapBuilder.prototype.toCSS = function(rootNode, options, imports) {
      var sourceMapOutput = new SourceMapOutput(
        {
          contentsIgnoredCharsMap: imports.contentsIgnoredChars,
          rootNode: rootNode,
          contentsMap: imports.contents,
          sourceMapFilename: this.options.sourceMapFilename,
          sourceMapURL: this.options.sourceMapURL,
          outputFilename: this.options.sourceMapOutputFilename,
          sourceMapBasepath: this.options.sourceMapBasepath,
          sourceMapRootpath: this.options.sourceMapRootpath,
          outputSourceFiles: this.options.outputSourceFiles,
          sourceMapGenerator: this.options.sourceMapGenerator,
          sourceMapFileInline: this.options.sourceMapFileInline
        });

      var css = sourceMapOutput.toCSS(options);
      this.sourceMap = sourceMapOutput.sourceMap;
      this.sourceMapURL = sourceMapOutput.sourceMapURL;
      if (this.options.sourceMapInputFilename) {
        this.sourceMapInputFilename = sourceMapOutput.normalizeFilename(this.options.sourceMapInputFilename);
      }
      return css + this.getCSSAppendage();
    };

    SourceMapBuilder.prototype.getCSSAppendage = function() {

      var sourceMapURL = this.sourceMapURL;
      if (this.options.sourceMapFileInline) {
        if (this.sourceMap === undefined) {
          return "";
        }
        sourceMapURL = "data:application/json;base64," + environment.encodeBase64(this.sourceMap);
      }

      if (sourceMapURL) {
        return "/*# sourceMappingURL=" + sourceMapURL + " */";
      }
      return "";
    };

    SourceMapBuilder.prototype.getExternalSourceMap = function() {
      return this.sourceMap;
    };
    SourceMapBuilder.prototype.setExternalSourceMap = function(sourceMap) {
      this.sourceMap = sourceMap;
    };

    SourceMapBuilder.prototype.isInline = function() {
      return this.options.sourceMapFileInline;
    };
    SourceMapBuilder.prototype.getSourceMapURL = function() {
      return this.sourceMapURL;
    };
    SourceMapBuilder.prototype.getOutputFilename = function() {
      return this.options.sourceMapOutputFilename;
    };
    SourceMapBuilder.prototype.getInputFilename = function() {
      return this.sourceMapInputFilename;
    };

    return SourceMapBuilder;
  };

},{}],43:[function(require,module,exports){
  module.exports = function (environment) {

    var SourceMapOutput = function (options) {
      this._css = [];
      this._rootNode = options.rootNode;
      this._contentsMap = options.contentsMap;
      this._contentsIgnoredCharsMap = options.contentsIgnoredCharsMap;
      if (options.sourceMapFilename) {
        this._sourceMapFilename = options.sourceMapFilename.replace(/\\/g, '/');
      }
      this._outputFilename = options.outputFilename;
      this.sourceMapURL = options.sourceMapURL;
      if (options.sourceMapBasepath) {
        this._sourceMapBasepath = options.sourceMapBasepath.replace(/\\/g, '/');
      }
      if (options.sourceMapRootpath) {
        this._sourceMapRootpath = options.sourceMapRootpath.replace(/\\/g, '/');
        if (this._sourceMapRootpath.charAt(this._sourceMapRootpath.length - 1) !== '/') {
          this._sourceMapRootpath += '/';
        }
      } else {
        this._sourceMapRootpath = "";
      }
      this._outputSourceFiles = options.outputSourceFiles;
      this._sourceMapGeneratorConstructor = environment.getSourceMapGenerator();

      this._lineNumber = 0;
      this._column = 0;
    };

    SourceMapOutput.prototype.normalizeFilename = function(filename) {
      filename = filename.replace(/\\/g, '/');

      if (this._sourceMapBasepath && filename.indexOf(this._sourceMapBasepath) === 0) {
        filename = filename.substring(this._sourceMapBasepath.length);
        if (filename.charAt(0) === '\\' || filename.charAt(0) === '/') {
          filename = filename.substring(1);
        }
      }
      return (this._sourceMapRootpath || "") + filename;
    };

    SourceMapOutput.prototype.add = function(chunk, fileInfo, index, mapLines) {

      //ignore adding empty strings
      if (!chunk) {
        return;
      }

      var lines,
        sourceLines,
        columns,
        sourceColumns,
        i;

      if (fileInfo) {
        var inputSource = this._contentsMap[fileInfo.filename];

        // remove vars/banner added to the top of the file
        if (this._contentsIgnoredCharsMap[fileInfo.filename]) {
          // adjust the index
          index -= this._contentsIgnoredCharsMap[fileInfo.filename];
          if (index < 0) { index = 0; }
          // adjust the source
          inputSource = inputSource.slice(this._contentsIgnoredCharsMap[fileInfo.filename]);
        }
        inputSource = inputSource.substring(0, index);
        sourceLines = inputSource.split("\n");
        sourceColumns = sourceLines[sourceLines.length - 1];
      }

      lines = chunk.split("\n");
      columns = lines[lines.length - 1];

      if (fileInfo) {
        if (!mapLines) {
          this._sourceMapGenerator.addMapping({ generated: { line: this._lineNumber + 1, column: this._column},
            original: { line: sourceLines.length, column: sourceColumns.length},
            source: this.normalizeFilename(fileInfo.filename)});
        } else {
          for (i = 0; i < lines.length; i++) {
            this._sourceMapGenerator.addMapping({ generated: { line: this._lineNumber + i + 1, column: i === 0 ? this._column : 0},
              original: { line: sourceLines.length + i, column: i === 0 ? sourceColumns.length : 0},
              source: this.normalizeFilename(fileInfo.filename)});
          }
        }
      }

      if (lines.length === 1) {
        this._column += columns.length;
      } else {
        this._lineNumber += lines.length - 1;
        this._column = columns.length;
      }

      this._css.push(chunk);
    };

    SourceMapOutput.prototype.isEmpty = function() {
      return this._css.length === 0;
    };

    SourceMapOutput.prototype.toCSS = function(context) {
      this._sourceMapGenerator = new this._sourceMapGeneratorConstructor({ file: this._outputFilename, sourceRoot: null });

      if (this._outputSourceFiles) {
        for (var filename in this._contentsMap) {
          if (this._contentsMap.hasOwnProperty(filename)) {
            var source = this._contentsMap[filename];
            if (this._contentsIgnoredCharsMap[filename]) {
              source = source.slice(this._contentsIgnoredCharsMap[filename]);
            }
            this._sourceMapGenerator.setSourceContent(this.normalizeFilename(filename), source);
          }
        }
      }

      this._rootNode.genCSS(context, this);

      if (this._css.length > 0) {
        var sourceMapURL,
          sourceMapContent = JSON.stringify(this._sourceMapGenerator.toJSON());

        if (this.sourceMapURL) {
          sourceMapURL = this.sourceMapURL;
        } else if (this._sourceMapFilename) {
          sourceMapURL = this._sourceMapFilename;
        }
        this.sourceMapURL = sourceMapURL;

        this.sourceMap = sourceMapContent;
      }

      return this._css.join('');
    };

    return SourceMapOutput;
  };

},{}],44:[function(require,module,exports){
  var contexts = require("./contexts"),
    visitor = require("./visitors"),
    tree = require("./tree");

  module.exports = function(root, options) {
    options = options || {};
    var evaldRoot,
      variables = options.variables,
      evalEnv = new contexts.Eval(options);

    //
    // Allows setting variables with a hash, so:
    //
    //   `{ color: new tree.Color('#f01') }` will become:
    //
    //   new tree.Rule('@color',
    //     new tree.Value([
    //       new tree.Expression([
    //         new tree.Color('#f01')
    //       ])
    //     ])
    //   )
    //
    if (typeof variables === 'object' && !Array.isArray(variables)) {
      variables = Object.keys(variables).map(function (k) {
        var value = variables[k];

        if (! (value instanceof tree.Value)) {
          if (! (value instanceof tree.Expression)) {
            value = new tree.Expression([value]);
          }
          value = new tree.Value([value]);
        }
        return new tree.Rule('@' + k, value, false, null, 0);
      });
      evalEnv.frames = [new tree.Ruleset(null, variables)];
    }

    var preEvalVisitors = [],
      visitors = [
        new visitor.JoinSelectorVisitor(),
        new visitor.MarkVisibleSelectorsVisitor(true),
        new visitor.ExtendVisitor(),
        new visitor.ToCSSVisitor({compress: Boolean(options.compress)})
      ], i;

    if (options.pluginManager) {
      var pluginVisitors = options.pluginManager.getVisitors();
      for (i = 0; i < pluginVisitors.length; i++) {
        var pluginVisitor = pluginVisitors[i];
        if (pluginVisitor.isPreEvalVisitor) {
          preEvalVisitors.push(pluginVisitor);
        } else {
          if (pluginVisitor.isPreVisitor) {
            visitors.splice(0, 0, pluginVisitor);
          } else {
            visitors.push(pluginVisitor);
          }
        }
      }
    }

    for (i = 0; i < preEvalVisitors.length; i++) {
      preEvalVisitors[i].run(root);
    }

    evaldRoot = root.eval(evalEnv);

    for (i = 0; i < visitors.length; i++) {
      visitors[i].run(evaldRoot);
    }

    return evaldRoot;
  };

},{"./contexts":11,"./tree":62,"./visitors":87}],45:[function(require,module,exports){
  var Node = require("./node");

  var Alpha = function (val) {
    this.value = val;
  };
  Alpha.prototype = new Node();
  Alpha.prototype.type = "Alpha";

  Alpha.prototype.accept = function (visitor) {
    this.value = visitor.visit(this.value);
  };
  Alpha.prototype.eval = function (context) {
    if (this.value.eval) { return new Alpha(this.value.eval(context)); }
    return this;
  };
  Alpha.prototype.genCSS = function (context, output) {
    output.add("alpha(opacity=");

    if (this.value.genCSS) {
      this.value.genCSS(context, output);
    } else {
      output.add(this.value);
    }

    output.add(")");
  };

  module.exports = Alpha;

},{"./node":70}],46:[function(require,module,exports){
  var Node = require("./node");

  var Anonymous = function (value, index, currentFileInfo, mapLines, rulesetLike, visibilityInfo) {
    this.value = value;
    this.index = index;
    this.mapLines = mapLines;
    this.currentFileInfo = currentFileInfo;
    this.rulesetLike = (typeof rulesetLike === 'undefined') ? false : rulesetLike;
    this.allowRoot = true;
    this.copyVisibilityInfo(visibilityInfo);
  };
  Anonymous.prototype = new Node();
  Anonymous.prototype.type = "Anonymous";
  Anonymous.prototype.eval = function () {
    return new Anonymous(this.value, this.index, this.currentFileInfo, this.mapLines, this.rulesetLike, this.visibilityInfo());
  };
  Anonymous.prototype.compare = function (other) {
    return other.toCSS && this.toCSS() === other.toCSS() ? 0 : undefined;
  };
  Anonymous.prototype.isRulesetLike = function() {
    return this.rulesetLike;
  };
  Anonymous.prototype.genCSS = function (context, output) {
    output.add(this.value, this.currentFileInfo, this.index, this.mapLines);
  };
  module.exports = Anonymous;

},{"./node":70}],47:[function(require,module,exports){
  var Node = require("./node");

  var Assignment = function (key, val) {
    this.key = key;
    this.value = val;
  };

  Assignment.prototype = new Node();
  Assignment.prototype.type = "Assignment";
  Assignment.prototype.accept = function (visitor) {
    this.value = visitor.visit(this.value);
  };
  Assignment.prototype.eval = function (context) {
    if (this.value.eval) {
      return new Assignment(this.key, this.value.eval(context));
    }
    return this;
  };
  Assignment.prototype.genCSS = function (context, output) {
    output.add(this.key + '=');
    if (this.value.genCSS) {
      this.value.genCSS(context, output);
    } else {
      output.add(this.value);
    }
  };
  module.exports = Assignment;

},{"./node":70}],48:[function(require,module,exports){
  var Node = require("./node");

  var Attribute = function (key, op, value) {
    this.key = key;
    this.op = op;
    this.value = value;
  };
  Attribute.prototype = new Node();
  Attribute.prototype.type = "Attribute";
  Attribute.prototype.eval = function (context) {
    return new Attribute(this.key.eval ? this.key.eval(context) : this.key,
      this.op, (this.value && this.value.eval) ? this.value.eval(context) : this.value);
  };
  Attribute.prototype.genCSS = function (context, output) {
    output.add(this.toCSS(context));
  };
  Attribute.prototype.toCSS = function (context) {
    var value = this.key.toCSS ? this.key.toCSS(context) : this.key;

    if (this.op) {
      value += this.op;
      value += (this.value.toCSS ? this.value.toCSS(context) : this.value);
    }

    return '[' + value + ']';
  };
  module.exports = Attribute;

},{"./node":70}],49:[function(require,module,exports){
  var Node = require("./node"),
    FunctionCaller = require("../functions/function-caller");
//
// A function call node.
//
  var Call = function (name, args, index, currentFileInfo) {
    this.name = name;
    this.args = args;
    this.index = index;
    this.currentFileInfo = currentFileInfo;
  };
  Call.prototype = new Node();
  Call.prototype.type = "Call";
  Call.prototype.accept = function (visitor) {
    if (this.args) {
      this.args = visitor.visitArray(this.args);
    }
  };
//
// When evaluating a function call,
// we either find the function in the functionRegistry,
// in which case we call it, passing the  evaluated arguments,
// if this returns null or we cannot find the function, we
// simply print it out as it appeared originally [2].
//
// The reason why we evaluate the arguments, is in the case where
// we try to pass a variable to a function, like: `saturate(@color)`.
// The function should receive the value, not the variable.
//
  Call.prototype.eval = function (context) {
    var args = this.args.map(function (a) { return a.eval(context); }),
      result, funcCaller = new FunctionCaller(this.name, context, this.index, this.currentFileInfo);

    if (funcCaller.isValid()) {
      try {
        result = funcCaller.call(args);
      } catch (e) {
        throw { type: e.type || "Runtime",
          message: "error evaluating function `" + this.name + "`" +
          (e.message ? ': ' + e.message : ''),
          index: this.index, filename: this.currentFileInfo.filename };
      }

      if (result != null) {
        result.index = this.index;
        result.currentFileInfo = this.currentFileInfo;
        return result;
      }
    }

    return new Call(this.name, args, this.index, this.currentFileInfo);
  };
  Call.prototype.genCSS = function (context, output) {
    output.add(this.name + "(", this.currentFileInfo, this.index);

    for (var i = 0; i < this.args.length; i++) {
      this.args[i].genCSS(context, output);
      if (i + 1 < this.args.length) {
        output.add(", ");
      }
    }

    output.add(")");
  };
  module.exports = Call;

},{"../functions/function-caller":21,"./node":70}],50:[function(require,module,exports){
  var Node = require("./node"),
    colors = require("../data/colors");

//
// RGB Colors - #ff0014, #eee
//
  var Color = function (rgb, a, originalForm) {
    //
    // The end goal here, is to parse the arguments
    // into an integer triplet, such as `128, 255, 0`
    //
    // This facilitates operations and conversions.
    //
    if (Array.isArray(rgb)) {
      this.rgb = rgb;
    } else if (rgb.length == 6) {
      this.rgb = rgb.match(/.{2}/g).map(function (c) {
        return parseInt(c, 16);
      });
    } else {
      this.rgb = rgb.split('').map(function (c) {
        return parseInt(c + c, 16);
      });
    }
    this.alpha = typeof a === 'number' ? a : 1;
    if (typeof originalForm !== 'undefined') {
      this.value = originalForm;
    }
  };

  Color.prototype = new Node();
  Color.prototype.type = "Color";

  function clamp(v, max) {
    return Math.min(Math.max(v, 0), max);
  }

  function toHex(v) {
    return '#' + v.map(function (c) {
      c = clamp(Math.round(c), 255);
      return (c < 16 ? '0' : '') + c.toString(16);
    }).join('');
  }

  Color.prototype.luma = function () {
    var r = this.rgb[0] / 255,
      g = this.rgb[1] / 255,
      b = this.rgb[2] / 255;

    r = (r <= 0.03928) ? r / 12.92 : Math.pow(((r + 0.055) / 1.055), 2.4);
    g = (g <= 0.03928) ? g / 12.92 : Math.pow(((g + 0.055) / 1.055), 2.4);
    b = (b <= 0.03928) ? b / 12.92 : Math.pow(((b + 0.055) / 1.055), 2.4);

    return 0.2126 * r + 0.7152 * g + 0.0722 * b;
  };
  Color.prototype.genCSS = function (context, output) {
    output.add(this.toCSS(context));
  };
  Color.prototype.toCSS = function (context, doNotCompress) {
    var compress = context && context.compress && !doNotCompress, color, alpha;

    // `value` is set if this color was originally
    // converted from a named color string so we need
    // to respect this and try to output named color too.
    if (this.value) {
      return this.value;
    }

    // If we have some transparency, the only way to represent it
    // is via `rgba`. Otherwise, we use the hex representation,
    // which has better compatibility with older browsers.
    // Values are capped between `0` and `255`, rounded and zero-padded.
    alpha = this.fround(context, this.alpha);
    if (alpha < 1) {
      return "rgba(" + this.rgb.map(function (c) {
        return clamp(Math.round(c), 255);
      }).concat(clamp(alpha, 1))
        .join(',' + (compress ? '' : ' ')) + ")";
    }

    color = this.toRGB();

    if (compress) {
      var splitcolor = color.split('');

      // Convert color to short format
      if (splitcolor[1] === splitcolor[2] && splitcolor[3] === splitcolor[4] && splitcolor[5] === splitcolor[6]) {
        color = '#' + splitcolor[1] + splitcolor[3] + splitcolor[5];
      }
    }

    return color;
  };

//
// Operations have to be done per-channel, if not,
// channels will spill onto each other. Once we have
// our result, in the form of an integer triplet,
// we create a new Color node to hold the result.
//
  Color.prototype.operate = function (context, op, other) {
    var rgb = [];
    var alpha = this.alpha * (1 - other.alpha) + other.alpha;
    for (var c = 0; c < 3; c++) {
      rgb[c] = this._operate(context, op, this.rgb[c], other.rgb[c]);
    }
    return new Color(rgb, alpha);
  };
  Color.prototype.toRGB = function () {
    return toHex(this.rgb);
  };
  Color.prototype.toHSL = function () {
    var r = this.rgb[0] / 255,
      g = this.rgb[1] / 255,
      b = this.rgb[2] / 255,
      a = this.alpha;

    var max = Math.max(r, g, b), min = Math.min(r, g, b);
    var h, s, l = (max + min) / 2, d = max - min;

    if (max === min) {
      h = s = 0;
    } else {
      s = l > 0.5 ? d / (2 - max - min) : d / (max + min);

      switch (max) {
        case r: h = (g - b) / d + (g < b ? 6 : 0); break;
        case g: h = (b - r) / d + 2;               break;
        case b: h = (r - g) / d + 4;               break;
      }
      h /= 6;
    }
    return { h: h * 360, s: s, l: l, a: a };
  };
//Adapted from http://mjijackson.com/2008/02/rgb-to-hsl-and-rgb-to-hsv-color-model-conversion-algorithms-in-javascript
  Color.prototype.toHSV = function () {
    var r = this.rgb[0] / 255,
      g = this.rgb[1] / 255,
      b = this.rgb[2] / 255,
      a = this.alpha;

    var max = Math.max(r, g, b), min = Math.min(r, g, b);
    var h, s, v = max;

    var d = max - min;
    if (max === 0) {
      s = 0;
    } else {
      s = d / max;
    }

    if (max === min) {
      h = 0;
    } else {
      switch(max) {
        case r: h = (g - b) / d + (g < b ? 6 : 0); break;
        case g: h = (b - r) / d + 2; break;
        case b: h = (r - g) / d + 4; break;
      }
      h /= 6;
    }
    return { h: h * 360, s: s, v: v, a: a };
  };
  Color.prototype.toARGB = function () {
    return toHex([this.alpha * 255].concat(this.rgb));
  };
  Color.prototype.compare = function (x) {
    return (x.rgb &&
      x.rgb[0] === this.rgb[0] &&
      x.rgb[1] === this.rgb[1] &&
      x.rgb[2] === this.rgb[2] &&
      x.alpha  === this.alpha) ? 0 : undefined;
  };

  Color.fromKeyword = function(keyword) {
    var c, key = keyword.toLowerCase();
    if (colors.hasOwnProperty(key)) {
      c = new Color(colors[key].slice(1));
    }
    else if (key === "transparent") {
      c = new Color([0, 0, 0], 0);
    }

    if (c) {
      c.value = keyword;
      return c;
    }
  };
  module.exports = Color;

},{"../data/colors":12,"./node":70}],51:[function(require,module,exports){
  var Node = require("./node");

  var Combinator = function (value) {
    if (value === ' ') {
      this.value = ' ';
      this.emptyOrWhitespace = true;
    } else {
      this.value = value ? value.trim() : "";
      this.emptyOrWhitespace = this.value === "";
    }
  };
  Combinator.prototype = new Node();
  Combinator.prototype.type = "Combinator";
  var _noSpaceCombinators = {
    '': true,
    ' ': true,
    '|': true
  };
  Combinator.prototype.genCSS = function (context, output) {
    var spaceOrEmpty = (context.compress || _noSpaceCombinators[this.value]) ? '' : ' ';
    output.add(spaceOrEmpty + this.value + spaceOrEmpty);
  };
  module.exports = Combinator;

},{"./node":70}],52:[function(require,module,exports){
  var Node = require("./node"),
    getDebugInfo = require("./debug-info");

  var Comment = function (value, isLineComment, index, currentFileInfo) {
    this.value = value;
    this.isLineComment = isLineComment;
    this.index = index;
    this.currentFileInfo = currentFileInfo;
    this.allowRoot = true;
  };
  Comment.prototype = new Node();
  Comment.prototype.type = "Comment";
  Comment.prototype.genCSS = function (context, output) {
    if (this.debugInfo) {
      output.add(getDebugInfo(context, this), this.currentFileInfo, this.index);
    }
    output.add(this.value);
  };
  Comment.prototype.isSilent = function(context) {
    var isCompressed = context.compress && this.value[2] !== "!";
    return this.isLineComment || isCompressed;
  };
  module.exports = Comment;

},{"./debug-info":54,"./node":70}],53:[function(require,module,exports){
  var Node = require("./node");

  var Condition = function (op, l, r, i, negate) {
    this.op = op.trim();
    this.lvalue = l;
    this.rvalue = r;
    this.index = i;
    this.negate = negate;
  };
  Condition.prototype = new Node();
  Condition.prototype.type = "Condition";
  Condition.prototype.accept = function (visitor) {
    this.lvalue = visitor.visit(this.lvalue);
    this.rvalue = visitor.visit(this.rvalue);
  };
  Condition.prototype.eval = function (context) {
    var result = (function (op, a, b) {
      switch (op) {
        case 'and': return a && b;
        case 'or':  return a || b;
        default:
          switch (Node.compare(a, b)) {
            case -1:
              return op === '<' || op === '=<' || op === '<=';
            case 0:
              return op === '=' || op === '>=' || op === '=<' || op === '<=';
            case 1:
              return op === '>' || op === '>=';
            default:
              return false;
          }
      }
    })(this.op, this.lvalue.eval(context), this.rvalue.eval(context));

    return this.negate ? !result : result;
  };
  module.exports = Condition;

},{"./node":70}],54:[function(require,module,exports){
  var debugInfo = function(context, ctx, lineSeparator) {
    var result = "";
    if (context.dumpLineNumbers && !context.compress) {
      switch(context.dumpLineNumbers) {
        case 'comments':
          result = debugInfo.asComment(ctx);
          break;
        case 'mediaquery':
          result = debugInfo.asMediaQuery(ctx);
          break;
        case 'all':
          result = debugInfo.asComment(ctx) + (lineSeparator || "") + debugInfo.asMediaQuery(ctx);
          break;
      }
    }
    return result;
  };

  debugInfo.asComment = function(ctx) {
    return '/* line ' + ctx.debugInfo.lineNumber + ', ' + ctx.debugInfo.fileName + ' */\n';
  };

  debugInfo.asMediaQuery = function(ctx) {
    var filenameWithProtocol = ctx.debugInfo.fileName;
    if (!/^[a-z]+:\/\//i.test(filenameWithProtocol)) {
      filenameWithProtocol = 'file://' + filenameWithProtocol;
    }
    return '@media -sass-debug-info{filename{font-family:' +
      filenameWithProtocol.replace(/([.:\/\\])/g, function (a) {
        if (a == '\\') {
          a = '\/';
        }
        return '\\' + a;
      }) +
      '}line{font-family:\\00003' + ctx.debugInfo.lineNumber + '}}\n';
  };

  module.exports = debugInfo;

},{}],55:[function(require,module,exports){
  var Node = require("./node"),
    contexts = require("../contexts");

  var DetachedRuleset = function (ruleset, frames) {
    this.ruleset = ruleset;
    this.frames = frames;
  };
  DetachedRuleset.prototype = new Node();
  DetachedRuleset.prototype.type = "DetachedRuleset";
  DetachedRuleset.prototype.evalFirst = true;
  DetachedRuleset.prototype.accept = function (visitor) {
    this.ruleset = visitor.visit(this.ruleset);
  };
  DetachedRuleset.prototype.eval = function (context) {
    var frames = this.frames || context.frames.slice(0);
    return new DetachedRuleset(this.ruleset, frames);
  };
  DetachedRuleset.prototype.callEval = function (context) {
    return this.ruleset.eval(this.frames ? new contexts.Eval(context, this.frames.concat(context.frames)) : context);
  };
  module.exports = DetachedRuleset;

},{"../contexts":11,"./node":70}],56:[function(require,module,exports){
  var Node = require("./node"),
    unitConversions = require("../data/unit-conversions"),
    Unit = require("./unit"),
    Color = require("./color");

//
// A number with a unit
//
  var Dimension = function (value, unit) {
    this.value = parseFloat(value);
    this.unit = (unit && unit instanceof Unit) ? unit :
      new Unit(unit ? [unit] : undefined);
  };

  Dimension.prototype = new Node();
  Dimension.prototype.type = "Dimension";
  Dimension.prototype.accept = function (visitor) {
    this.unit = visitor.visit(this.unit);
  };
  Dimension.prototype.eval = function (context) {
    return this;
  };
  Dimension.prototype.toColor = function () {
    return new Color([this.value, this.value, this.value]);
  };
  Dimension.prototype.genCSS = function (context, output) {
    if ((context && context.strictUnits) && !this.unit.isSingular()) {
      throw new Error("Multiple units in dimension. Correct the units or use the unit function. Bad unit: " + this.unit.toString());
    }

    var value = this.fround(context, this.value),
      strValue = String(value);

    if (value !== 0 && value < 0.000001 && value > -0.000001) {
      // would be output 1e-6 etc.
      strValue = value.toFixed(20).replace(/0+$/, "");
    }

    if (context && context.compress) {
      // Zero values doesn't need a unit
      if (value === 0 && this.unit.isLength()) {
        output.add(strValue);
        return;
      }

      // Float values doesn't need a leading zero
      if (value > 0 && value < 1) {
        strValue = (strValue).substr(1);
      }
    }

    output.add(strValue);
    this.unit.genCSS(context, output);
  };

// In an operation between two Dimensions,
// we default to the first Dimension's unit,
// so `1px + 2` will yield `3px`.
  Dimension.prototype.operate = function (context, op, other) {
    /*jshint noempty:false */
    var value = this._operate(context, op, this.value, other.value),
      unit = this.unit.clone();

    if (op === '+' || op === '-') {
      if (unit.numerator.length === 0 && unit.denominator.length === 0) {
        unit = other.unit.clone();
        if (this.unit.backupUnit) {
          unit.backupUnit = this.unit.backupUnit;
        }
      } else if (other.unit.numerator.length === 0 && unit.denominator.length === 0) {
        // do nothing
      } else {
        other = other.convertTo(this.unit.usedUnits());

        if (context.strictUnits && other.unit.toString() !== unit.toString()) {
          throw new Error("Incompatible units. Change the units or use the unit function. Bad units: '" + unit.toString() +
            "' and '" + other.unit.toString() + "'.");
        }

        value = this._operate(context, op, this.value, other.value);
      }
    } else if (op === '*') {
      unit.numerator = unit.numerator.concat(other.unit.numerator).sort();
      unit.denominator = unit.denominator.concat(other.unit.denominator).sort();
      unit.cancel();
    } else if (op === '/') {
      unit.numerator = unit.numerator.concat(other.unit.denominator).sort();
      unit.denominator = unit.denominator.concat(other.unit.numerator).sort();
      unit.cancel();
    }
    return new Dimension(value, unit);
  };
  Dimension.prototype.compare = function (other) {
    var a, b;

    if (!(other instanceof Dimension)) {
      return undefined;
    }

    if (this.unit.isEmpty() || other.unit.isEmpty()) {
      a = this;
      b = other;
    } else {
      a = this.unify();
      b = other.unify();
      if (a.unit.compare(b.unit) !== 0) {
        return undefined;
      }
    }

    return Node.numericCompare(a.value, b.value);
  };
  Dimension.prototype.unify = function () {
    return this.convertTo({ length: 'px', duration: 's', angle: 'rad' });
  };
  Dimension.prototype.convertTo = function (conversions) {
    var value = this.value, unit = this.unit.clone(),
      i, groupName, group, targetUnit, derivedConversions = {}, applyUnit;

    if (typeof conversions === 'string') {
      for (i in unitConversions) {
        if (unitConversions[i].hasOwnProperty(conversions)) {
          derivedConversions = {};
          derivedConversions[i] = conversions;
        }
      }
      conversions = derivedConversions;
    }
    applyUnit = function (atomicUnit, denominator) {
      /* jshint loopfunc:true */
      if (group.hasOwnProperty(atomicUnit)) {
        if (denominator) {
          value = value / (group[atomicUnit] / group[targetUnit]);
        } else {
          value = value * (group[atomicUnit] / group[targetUnit]);
        }

        return targetUnit;
      }

      return atomicUnit;
    };

    for (groupName in conversions) {
      if (conversions.hasOwnProperty(groupName)) {
        targetUnit = conversions[groupName];
        group = unitConversions[groupName];

        unit.map(applyUnit);
      }
    }

    unit.cancel();

    return new Dimension(value, unit);
  };
  module.exports = Dimension;

},{"../data/unit-conversions":14,"./color":50,"./node":70,"./unit":79}],57:[function(require,module,exports){
  var Node = require("./node"),
    Selector = require("./selector"),
    Ruleset = require("./ruleset");

  var Directive = function (name, value, rules, index, currentFileInfo, debugInfo, isRooted, visibilityInfo) {
    var i;

    this.name  = name;
    this.value = value;
    if (rules) {
      if (Array.isArray(rules)) {
        this.rules = rules;
      } else {
        this.rules = [rules];
        this.rules[0].selectors = (new Selector([], null, null, this.index, currentFileInfo)).createEmptySelectors();
      }
      for (i = 0; i < this.rules.length; i++) {
        this.rules[i].allowImports = true;
      }
    }
    this.index = index;
    this.currentFileInfo = currentFileInfo;
    this.debugInfo = debugInfo;
    this.isRooted = isRooted || false;
    this.copyVisibilityInfo(visibilityInfo);
    this.allowRoot = true;
  };

  Directive.prototype = new Node();
  Directive.prototype.type = "Directive";
  Directive.prototype.accept = function (visitor) {
    var value = this.value, rules = this.rules;
    if (rules) {
      this.rules = visitor.visitArray(rules);
    }
    if (value) {
      this.value = visitor.visit(value);
    }
  };
  Directive.prototype.isRulesetLike = function() {
    return this.rules || !this.isCharset();
  };
  Directive.prototype.isCharset = function() {
    return "@charset" === this.name;
  };
  Directive.prototype.genCSS = function (context, output) {
    var value = this.value, rules = this.rules;
    output.add(this.name, this.currentFileInfo, this.index);
    if (value) {
      output.add(' ');
      value.genCSS(context, output);
    }
    if (rules) {
      this.outputRuleset(context, output, rules);
    } else {
      output.add(';');
    }
  };
  Directive.prototype.eval = function (context) {
    var mediaPathBackup, mediaBlocksBackup, value = this.value, rules = this.rules;

    //media stored inside other directive should not bubble over it
    //backpup media bubbling information
    mediaPathBackup = context.mediaPath;
    mediaBlocksBackup = context.mediaBlocks;
    //deleted media bubbling information
    context.mediaPath = [];
    context.mediaBlocks = [];

    if (value) {
      value = value.eval(context);
    }
    if (rules) {
      // assuming that there is only one rule at this point - that is how parser constructs the rule
      rules = [rules[0].eval(context)];
      rules[0].root = true;
    }
    //restore media bubbling information
    context.mediaPath = mediaPathBackup;
    context.mediaBlocks = mediaBlocksBackup;

    return new Directive(this.name, value, rules,
      this.index, this.currentFileInfo, this.debugInfo, this.isRooted, this.visibilityInfo());
  };
  Directive.prototype.variable = function (name) {
    if (this.rules) {
      // assuming that there is only one rule at this point - that is how parser constructs the rule
      return Ruleset.prototype.variable.call(this.rules[0], name);
    }
  };
  Directive.prototype.find = function () {
    if (this.rules) {
      // assuming that there is only one rule at this point - that is how parser constructs the rule
      return Ruleset.prototype.find.apply(this.rules[0], arguments);
    }
  };
  Directive.prototype.rulesets = function () {
    if (this.rules) {
      // assuming that there is only one rule at this point - that is how parser constructs the rule
      return Ruleset.prototype.rulesets.apply(this.rules[0]);
    }
  };
  Directive.prototype.outputRuleset = function (context, output, rules) {
    var ruleCnt = rules.length, i;
    context.tabLevel = (context.tabLevel | 0) + 1;

    // Compressed
    if (context.compress) {
      output.add('{');
      for (i = 0; i < ruleCnt; i++) {
        rules[i].genCSS(context, output);
      }
      output.add('}');
      context.tabLevel--;
      return;
    }

    // Non-compressed
    var tabSetStr = '\n' + Array(context.tabLevel).join("  "), tabRuleStr = tabSetStr + "  ";
    if (!ruleCnt) {
      output.add(" {" + tabSetStr + '}');
    } else {
      output.add(" {" + tabRuleStr);
      rules[0].genCSS(context, output);
      for (i = 1; i < ruleCnt; i++) {
        output.add(tabRuleStr);
        rules[i].genCSS(context, output);
      }
      output.add(tabSetStr + '}');
    }

    context.tabLevel--;
  };
  module.exports = Directive;

},{"./node":70,"./ruleset":76,"./selector":77}],58:[function(require,module,exports){
  var Node = require("./node"),
    Paren = require("./paren"),
    Combinator = require("./combinator");

  var Element = function (combinator, value, index, currentFileInfo, info) {
    this.combinator = combinator instanceof Combinator ?
      combinator : new Combinator(combinator);

    if (typeof value === 'string') {
      this.value = value.trim();
    } else if (value) {
      this.value = value;
    } else {
      this.value = "";
    }
    this.index = index;
    this.currentFileInfo = currentFileInfo;
    this.copyVisibilityInfo(info);
  };
  Element.prototype = new Node();
  Element.prototype.type = "Element";
  Element.prototype.accept = function (visitor) {
    var value = this.value;
    this.combinator = visitor.visit(this.combinator);
    if (typeof value === "object") {
      this.value = visitor.visit(value);
    }
  };
  Element.prototype.eval = function (context) {
    return new Element(this.combinator,
      this.value.eval ? this.value.eval(context) : this.value,
      this.index,
      this.currentFileInfo, this.visibilityInfo());
  };
  Element.prototype.clone = function () {
    return new Element(this.combinator,
      this.value,
      this.index,
      this.currentFileInfo, this.visibilityInfo());
  };
  Element.prototype.genCSS = function (context, output) {
    output.add(this.toCSS(context), this.currentFileInfo, this.index);
  };
  Element.prototype.toCSS = function (context) {
    context = context || {};
    var value = this.value, firstSelector = context.firstSelector;
    if (value instanceof Paren) {
      // selector in parens should not be affected by outer selector
      // flags (breaks only interpolated selectors - see #1973)
      context.firstSelector = true;
    }
    value = value.toCSS ? value.toCSS(context) : value;
    context.firstSelector = firstSelector;
    if (value === '' && this.combinator.value.charAt(0) === '&') {
      return '';
    } else {
      return this.combinator.toCSS(context) + value;
    }
  };
  module.exports = Element;

},{"./combinator":51,"./node":70,"./paren":72}],59:[function(require,module,exports){
  var Node = require("./node"),
    Paren = require("./paren"),
    Comment = require("./comment");

  var Expression = function (value) {
    this.value = value;
    if (!value) {
      throw new Error("Expression requires an array parameter");
    }
  };
  Expression.prototype = new Node();
  Expression.prototype.type = "Expression";
  Expression.prototype.accept = function (visitor) {
    this.value = visitor.visitArray(this.value);
  };
  Expression.prototype.eval = function (context) {
    var returnValue,
      inParenthesis = this.parens && !this.parensInOp,
      doubleParen = false;
    if (inParenthesis) {
      context.inParenthesis();
    }
    if (this.value.length > 1) {
      returnValue = new Expression(this.value.map(function (e) {
        return e.eval(context);
      }));
    } else if (this.value.length === 1) {
      if (this.value[0].parens && !this.value[0].parensInOp) {
        doubleParen = true;
      }
      returnValue = this.value[0].eval(context);
    } else {
      returnValue = this;
    }
    if (inParenthesis) {
      context.outOfParenthesis();
    }
    if (this.parens && this.parensInOp && !(context.isMathOn()) && !doubleParen) {
      returnValue = new Paren(returnValue);
    }
    return returnValue;
  };
  Expression.prototype.genCSS = function (context, output) {
    for (var i = 0; i < this.value.length; i++) {
      this.value[i].genCSS(context, output);
      if (i + 1 < this.value.length) {
        output.add(" ");
      }
    }
  };
  Expression.prototype.throwAwayComments = function () {
    this.value = this.value.filter(function(v) {
      return !(v instanceof Comment);
    });
  };
  module.exports = Expression;

},{"./comment":52,"./node":70,"./paren":72}],60:[function(require,module,exports){
  var Node = require("./node"),
    Selector = require("./selector");

  var Extend = function Extend(selector, option, index, currentFileInfo, visibilityInfo) {
    this.selector = selector;
    this.option = option;
    this.index = index;
    this.object_id = Extend.next_id++;
    this.parent_ids = [this.object_id];
    this.currentFileInfo = currentFileInfo || {};
    this.copyVisibilityInfo(visibilityInfo);
    this.allowRoot = true;

    switch(option) {
      case "all":
        this.allowBefore = true;
        this.allowAfter = true;
        break;
      default:
        this.allowBefore = false;
        this.allowAfter = false;
        break;
    }
  };
  Extend.next_id = 0;

  Extend.prototype = new Node();
  Extend.prototype.type = "Extend";
  Extend.prototype.accept = function (visitor) {
    this.selector = visitor.visit(this.selector);
  };
  Extend.prototype.eval = function (context) {
    return new Extend(this.selector.eval(context), this.option, this.index, this.currentFileInfo, this.visibilityInfo());
  };
  Extend.prototype.clone = function (context) {
    return new Extend(this.selector, this.option, this.index, this.currentFileInfo, this.visibilityInfo());
  };
//it concatenates (joins) all selectors in selector array
  Extend.prototype.findSelfSelectors = function (selectors) {
    var selfElements = [],
      i,
      selectorElements;

    for (i = 0; i < selectors.length; i++) {
      selectorElements = selectors[i].elements;
      // duplicate the logic in genCSS function inside the selector node.
      // future TODO - move both logics into the selector joiner visitor
      if (i > 0 && selectorElements.length && selectorElements[0].combinator.value === "") {
        selectorElements[0].combinator.value = ' ';
      }
      selfElements = selfElements.concat(selectors[i].elements);
    }

    this.selfSelectors = [new Selector(selfElements)];
    this.selfSelectors[0].copyVisibilityInfo(this.visibilityInfo());
  };
  module.exports = Extend;

},{"./node":70,"./selector":77}],61:[function(require,module,exports){
  var Node = require("./node"),
    Media = require("./media"),
    URL = require("./url"),
    Quoted = require("./quoted"),
    Ruleset = require("./ruleset"),
    Anonymous = require("./anonymous");

//
// CSS @import node
//
// The general strategy here is that we don't want to wait
// for the parsing to be completed, before we start importing
// the file. That's because in the context of a browser,
// most of the time will be spent waiting for the server to respond.
//
// On creation, we push the import path to our import queue, though
// `import,push`, we also pass it a callback, which it'll call once
// the file has been fetched, and parsed.
//
  var Import = function (path, features, options, index, currentFileInfo, visibilityInfo) {
    this.options = options;
    this.index = index;
    this.path = path;
    this.features = features;
    this.currentFileInfo = currentFileInfo;
    this.allowRoot = true;

    if (this.options.less !== undefined || this.options.inline) {
      this.css = !this.options.less || this.options.inline;
    } else {
      var pathValue = this.getPath();
      if (pathValue && /[#\.\&\?\/]css([\?;].*)?$/.test(pathValue)) {
        this.css = true;
      }
    }
    this.copyVisibilityInfo(visibilityInfo);
  };

//
// The actual import node doesn't return anything, when converted to CSS.
// The reason is that it's used at the evaluation stage, so that the rules
// it imports can be treated like any other rules.
//
// In `eval`, we make sure all Import nodes get evaluated, recursively, so
// we end up with a flat structure, which can easily be imported in the parent
// ruleset.
//
  Import.prototype = new Node();
  Import.prototype.type = "Import";
  Import.prototype.accept = function (visitor) {
    if (this.features) {
      this.features = visitor.visit(this.features);
    }
    this.path = visitor.visit(this.path);
    if (!this.options.plugin && !this.options.inline && this.root) {
      this.root = visitor.visit(this.root);
    }
  };
  Import.prototype.genCSS = function (context, output) {
    if (this.css && this.path.currentFileInfo.reference === undefined) {
      output.add("@import ", this.currentFileInfo, this.index);
      this.path.genCSS(context, output);
      if (this.features) {
        output.add(" ");
        this.features.genCSS(context, output);
      }
      output.add(';');
    }
  };
  Import.prototype.getPath = function () {
    return (this.path instanceof URL) ?
      this.path.value.value : this.path.value;
  };
  Import.prototype.isVariableImport = function () {
    var path = this.path;
    if (path instanceof URL) {
      path = path.value;
    }
    if (path instanceof Quoted) {
      return path.containsVariables();
    }

    return true;
  };
  Import.prototype.evalForImport = function (context) {
    var path = this.path;

    if (path instanceof URL) {
      path = path.value;
    }

    return new Import(path.eval(context), this.features, this.options, this.index, this.currentFileInfo, this.visibilityInfo());
  };
  Import.prototype.evalPath = function (context) {
    var path = this.path.eval(context);
    var rootpath = this.currentFileInfo && this.currentFileInfo.rootpath;

    if (!(path instanceof URL)) {
      if (rootpath) {
        var pathValue = path.value;
        // Add the base path if the import is relative
        if (pathValue && context.isPathRelative(pathValue)) {
          path.value = rootpath + pathValue;
        }
      }
      path.value = context.normalizePath(path.value);
    }

    return path;
  };
  Import.prototype.eval = function (context) {
    var result = this.doEval(context);
    if (this.options.reference || this.blocksVisibility()) {
      if (result.length || result.length === 0) {
        result.forEach(function (node) {
            node.addVisibilityBlock();
          }
        );
      } else {
        result.addVisibilityBlock();
      }
    }
    return result;
  };
  Import.prototype.doEval = function (context) {
    var ruleset, registry,
      features = this.features && this.features.eval(context);

    if (this.options.plugin) {
      registry = context.frames[0] && context.frames[0].functionRegistry;
      if ( registry && this.root && this.root.functions ) {
        registry.addMultiple( this.root.functions );
      }
      return [];
    }

    if (this.skip) {
      if (typeof this.skip === "function") {
        this.skip = this.skip();
      }
      if (this.skip) {
        return [];
      }
    }
    if (this.options.inline) {
      var contents = new Anonymous(this.root, 0,
        {
          filename: this.importedFilename,
          reference: this.path.currentFileInfo && this.path.currentFileInfo.reference
        }, true, true);

      return this.features ? new Media([contents], this.features.value) : [contents];
    } else if (this.css) {
      var newImport = new Import(this.evalPath(context), features, this.options, this.index);
      if (!newImport.css && this.error) {
        throw this.error;
      }
      return newImport;
    } else {
      ruleset = new Ruleset(null, this.root.rules.slice(0));
      ruleset.evalImports(context);

      return this.features ? new Media(ruleset.rules, this.features.value) : ruleset.rules;
    }
  };
  module.exports = Import;

},{"./anonymous":46,"./media":66,"./node":70,"./quoted":73,"./ruleset":76,"./url":80}],62:[function(require,module,exports){
  var tree = {};

  tree.Node = require('./node');
  tree.Alpha = require('./alpha');
  tree.Color = require('./color');
  tree.Directive = require('./directive');
  tree.DetachedRuleset = require('./detached-ruleset');
  tree.Operation = require('./operation');
  tree.Dimension = require('./dimension');
  tree.Unit = require('./unit');
  tree.Keyword = require('./keyword');
  tree.Variable = require('./variable');
  tree.Ruleset = require('./ruleset');
  tree.Element = require('./element');
  tree.Attribute = require('./attribute');
  tree.Combinator = require('./combinator');
  tree.Selector = require('./selector');
  tree.Quoted = require('./quoted');
  tree.Expression = require('./expression');
  tree.Rule = require('./rule');
  tree.Call = require('./call');
  tree.URL = require('./url');
  tree.Import = require('./import');
  tree.mixin = {
    Call: require('./mixin-call'),
    Definition: require('./mixin-definition')
  };
  tree.Comment = require('./comment');
  tree.Anonymous = require('./anonymous');
  tree.Value = require('./value');
  tree.JavaScript = require('./javascript');
  tree.Assignment = require('./assignment');
  tree.Condition = require('./condition');
  tree.Paren = require('./paren');
  tree.Media = require('./media');
  tree.UnicodeDescriptor = require('./unicode-descriptor');
  tree.Negative = require('./negative');
  tree.Extend = require('./extend');
  tree.RulesetCall = require('./ruleset-call');

  module.exports = tree;

},{"./alpha":45,"./anonymous":46,"./assignment":47,"./attribute":48,"./call":49,"./color":50,"./combinator":51,"./comment":52,"./condition":53,"./detached-ruleset":55,"./dimension":56,"./directive":57,"./element":58,"./expression":59,"./extend":60,"./import":61,"./javascript":63,"./keyword":65,"./media":66,"./mixin-call":67,"./mixin-definition":68,"./negative":69,"./node":70,"./operation":71,"./paren":72,"./quoted":73,"./rule":74,"./ruleset":76,"./ruleset-call":75,"./selector":77,"./unicode-descriptor":78,"./unit":79,"./url":80,"./value":81,"./variable":82}],63:[function(require,module,exports){
  var JsEvalNode = require("./js-eval-node"),
    Dimension = require("./dimension"),
    Quoted = require("./quoted"),
    Anonymous = require("./anonymous");

  var JavaScript = function (string, escaped, index, currentFileInfo) {
    this.escaped = escaped;
    this.expression = string;
    this.index = index;
    this.currentFileInfo = currentFileInfo;
  };
  JavaScript.prototype = new JsEvalNode();
  JavaScript.prototype.type = "JavaScript";
  JavaScript.prototype.eval = function(context) {
    var result = this.evaluateJavaScript(this.expression, context);

    if (typeof result === 'number') {
      return new Dimension(result);
    } else if (typeof result === 'string') {
      return new Quoted('"' + result + '"', result, this.escaped, this.index);
    } else if (Array.isArray(result)) {
      return new Anonymous(result.join(', '));
    } else {
      return new Anonymous(result);
    }
  };

  module.exports = JavaScript;

},{"./anonymous":46,"./dimension":56,"./js-eval-node":64,"./quoted":73}],64:[function(require,module,exports){
  var Node = require("./node"),
    Variable = require("./variable");

  var JsEvalNode = function() {
  };
  JsEvalNode.prototype = new Node();

  JsEvalNode.prototype.evaluateJavaScript = function (expression, context) {
    var result,
      that = this,
      evalContext = {};

    if (context.javascriptEnabled !== undefined && !context.javascriptEnabled) {
      throw { message: "You are using JavaScript, which has been disabled.",
        filename: this.currentFileInfo.filename,
        index: this.index };
    }

    expression = expression.replace(/@\{([\w-]+)\}/g, function (_, name) {
      return that.jsify(new Variable('@' + name, that.index, that.currentFileInfo).eval(context));
    });

    try {
      expression = new Function('return (' + expression + ')');
    } catch (e) {
      throw { message: "JavaScript evaluation error: " + e.message + " from `" + expression + "`" ,
        filename: this.currentFileInfo.filename,
        index: this.index };
    }

    var variables = context.frames[0].variables();
    for (var k in variables) {
      if (variables.hasOwnProperty(k)) {
        /*jshint loopfunc:true */
        evalContext[k.slice(1)] = {
          value: variables[k].value,
          toJS: function () {
            return this.value.eval(context).toCSS();
          }
        };
      }
    }

    try {
      result = expression.call(evalContext);
    } catch (e) {
      throw { message: "JavaScript evaluation error: '" + e.name + ': ' + e.message.replace(/["]/g, "'") + "'" ,
        filename: this.currentFileInfo.filename,
        index: this.index };
    }
    return result;
  };
  JsEvalNode.prototype.jsify = function (obj) {
    if (Array.isArray(obj.value) && (obj.value.length > 1)) {
      return '[' + obj.value.map(function (v) { return v.toCSS(); }).join(', ') + ']';
    } else {
      return obj.toCSS();
    }
  };

  module.exports = JsEvalNode;

},{"./node":70,"./variable":82}],65:[function(require,module,exports){
  var Node = require("./node");

  var Keyword = function (value) { this.value = value; };
  Keyword.prototype = new Node();
  Keyword.prototype.type = "Keyword";
  Keyword.prototype.genCSS = function (context, output) {
    if (this.value === '%') { throw { type: "Syntax", message: "Invalid % without number" }; }
    output.add(this.value);
  };

  Keyword.True = new Keyword('true');
  Keyword.False = new Keyword('false');

  module.exports = Keyword;

},{"./node":70}],66:[function(require,module,exports){
  var Ruleset = require("./ruleset"),
    Value = require("./value"),
    Selector = require("./selector"),
    Anonymous = require("./anonymous"),
    Expression = require("./expression"),
    Directive = require("./directive");

  var Media = function (value, features, index, currentFileInfo, visibilityInfo) {
    this.index = index;
    this.currentFileInfo = currentFileInfo;

    var selectors = (new Selector([], null, null, this.index, this.currentFileInfo)).createEmptySelectors();

    this.features = new Value(features);
    this.rules = [new Ruleset(selectors, value)];
    this.rules[0].allowImports = true;
    this.copyVisibilityInfo(visibilityInfo);
    this.allowRoot = true;
  };
  Media.prototype = new Directive();
  Media.prototype.type = "Media";
  Media.prototype.isRulesetLike = true;
  Media.prototype.accept = function (visitor) {
    if (this.features) {
      this.features = visitor.visit(this.features);
    }
    if (this.rules) {
      this.rules = visitor.visitArray(this.rules);
    }
  };
  Media.prototype.genCSS = function (context, output) {
    output.add('@media ', this.currentFileInfo, this.index);
    this.features.genCSS(context, output);
    this.outputRuleset(context, output, this.rules);
  };
  Media.prototype.eval = function (context) {
    if (!context.mediaBlocks) {
      context.mediaBlocks = [];
      context.mediaPath = [];
    }

    var media = new Media(null, [], this.index, this.currentFileInfo, this.visibilityInfo());
    if (this.debugInfo) {
      this.rules[0].debugInfo = this.debugInfo;
      media.debugInfo = this.debugInfo;
    }
    var strictMathBypass = false;
    if (!context.strictMath) {
      strictMathBypass = true;
      context.strictMath = true;
    }
    try {
      media.features = this.features.eval(context);
    }
    finally {
      if (strictMathBypass) {
        context.strictMath = false;
      }
    }

    context.mediaPath.push(media);
    context.mediaBlocks.push(media);

    this.rules[0].functionRegistry = context.frames[0].functionRegistry.inherit();
    context.frames.unshift(this.rules[0]);
    media.rules = [this.rules[0].eval(context)];
    context.frames.shift();

    context.mediaPath.pop();

    return context.mediaPath.length === 0 ? media.evalTop(context) :
      media.evalNested(context);
  };
  Media.prototype.evalTop = function (context) {
    var result = this;

    // Render all dependent Media blocks.
    if (context.mediaBlocks.length > 1) {
      var selectors = (new Selector([], null, null, this.index, this.currentFileInfo)).createEmptySelectors();
      result = new Ruleset(selectors, context.mediaBlocks);
      result.multiMedia = true;
      result.copyVisibilityInfo(this.visibilityInfo());
    }

    delete context.mediaBlocks;
    delete context.mediaPath;

    return result;
  };
  Media.prototype.evalNested = function (context) {
    var i, value,
      path = context.mediaPath.concat([this]);

    // Extract the media-query conditions separated with `,` (OR).
    for (i = 0; i < path.length; i++) {
      value = path[i].features instanceof Value ?
        path[i].features.value : path[i].features;
      path[i] = Array.isArray(value) ? value : [value];
    }

    // Trace all permutations to generate the resulting media-query.
    //
    // (a, b and c) with nested (d, e) ->
    //    a and d
    //    a and e
    //    b and c and d
    //    b and c and e
    this.features = new Value(this.permute(path).map(function (path) {
      path = path.map(function (fragment) {
        return fragment.toCSS ? fragment : new Anonymous(fragment);
      });

      for (i = path.length - 1; i > 0; i--) {
        path.splice(i, 0, new Anonymous("and"));
      }

      return new Expression(path);
    }));

    // Fake a tree-node that doesn't output anything.
    return new Ruleset([], []);
  };
  Media.prototype.permute = function (arr) {
    if (arr.length === 0) {
      return [];
    } else if (arr.length === 1) {
      return arr[0];
    } else {
      var result = [];
      var rest = this.permute(arr.slice(1));
      for (var i = 0; i < rest.length; i++) {
        for (var j = 0; j < arr[0].length; j++) {
          result.push([arr[0][j]].concat(rest[i]));
        }
      }
      return result;
    }
  };
  Media.prototype.bubbleSelectors = function (selectors) {
    if (!selectors) {
      return;
    }
    this.rules = [new Ruleset(selectors.slice(0), [this.rules[0]])];
  };
  module.exports = Media;

},{"./anonymous":46,"./directive":57,"./expression":59,"./ruleset":76,"./selector":77,"./value":81}],67:[function(require,module,exports){
  var Node = require("./node"),
    Selector = require("./selector"),
    MixinDefinition = require("./mixin-definition"),
    defaultFunc = require("../functions/default");

  var MixinCall = function (elements, args, index, currentFileInfo, important) {
    this.selector = new Selector(elements);
    this.arguments = args || [];
    this.index = index;
    this.currentFileInfo = currentFileInfo;
    this.important = important;
    this.allowRoot = true;
  };
  MixinCall.prototype = new Node();
  MixinCall.prototype.type = "MixinCall";
  MixinCall.prototype.accept = function (visitor) {
    if (this.selector) {
      this.selector = visitor.visit(this.selector);
    }
    if (this.arguments.length) {
      this.arguments = visitor.visitArray(this.arguments);
    }
  };
  MixinCall.prototype.eval = function (context) {
    var mixins, mixin, mixinPath, args = [], arg, argValue,
      rules = [], match = false, i, m, f, isRecursive, isOneFound,
      candidates = [], candidate, conditionResult = [], defaultResult, defFalseEitherCase = -1,
      defNone = 0, defTrue = 1, defFalse = 2, count, originalRuleset, noArgumentsFilter;

    function calcDefGroup(mixin, mixinPath) {
      var f, p, namespace;

      for (f = 0; f < 2; f++) {
        conditionResult[f] = true;
        defaultFunc.value(f);
        for (p = 0; p < mixinPath.length && conditionResult[f]; p++) {
          namespace = mixinPath[p];
          if (namespace.matchCondition) {
            conditionResult[f] = conditionResult[f] && namespace.matchCondition(null, context);
          }
        }
        if (mixin.matchCondition) {
          conditionResult[f] = conditionResult[f] && mixin.matchCondition(args, context);
        }
      }
      if (conditionResult[0] || conditionResult[1]) {
        if (conditionResult[0] != conditionResult[1]) {
          return conditionResult[1] ?
            defTrue : defFalse;
        }

        return defNone;
      }
      return defFalseEitherCase;
    }

    for (i = 0; i < this.arguments.length; i++) {
      arg = this.arguments[i];
      argValue = arg.value.eval(context);
      if (arg.expand && Array.isArray(argValue.value)) {
        argValue = argValue.value;
        for (m = 0; m < argValue.length; m++) {
          args.push({value: argValue[m]});
        }
      } else {
        args.push({name: arg.name, value: argValue});
      }
    }

    noArgumentsFilter = function(rule) {return rule.matchArgs(null, context);};

    for (i = 0; i < context.frames.length; i++) {
      if ((mixins = context.frames[i].find(this.selector, null, noArgumentsFilter)).length > 0) {
        isOneFound = true;

        // To make `default()` function independent of definition order we have two "subpasses" here.
        // At first we evaluate each guard *twice* (with `default() == true` and `default() == false`),
        // and build candidate list with corresponding flags. Then, when we know all possible matches,
        // we make a final decision.

        for (m = 0; m < mixins.length; m++) {
          mixin = mixins[m].rule;
          mixinPath = mixins[m].path;
          isRecursive = false;
          for (f = 0; f < context.frames.length; f++) {
            if ((!(mixin instanceof MixinDefinition)) && mixin === (context.frames[f].originalRuleset || context.frames[f])) {
              isRecursive = true;
              break;
            }
          }
          if (isRecursive) {
            continue;
          }

          if (mixin.matchArgs(args, context)) {
            candidate = {mixin: mixin, group: calcDefGroup(mixin, mixinPath)};

            if (candidate.group !== defFalseEitherCase) {
              candidates.push(candidate);
            }

            match = true;
          }
        }

        defaultFunc.reset();

        count = [0, 0, 0];
        for (m = 0; m < candidates.length; m++) {
          count[candidates[m].group]++;
        }

        if (count[defNone] > 0) {
          defaultResult = defFalse;
        } else {
          defaultResult = defTrue;
          if ((count[defTrue] + count[defFalse]) > 1) {
            throw { type: 'Runtime',
              message: 'Ambiguous use of `default()` found when matching for `' + this.format(args) + '`',
              index: this.index, filename: this.currentFileInfo.filename };
          }
        }

        for (m = 0; m < candidates.length; m++) {
          candidate = candidates[m].group;
          if ((candidate === defNone) || (candidate === defaultResult)) {
            try {
              mixin = candidates[m].mixin;
              if (!(mixin instanceof MixinDefinition)) {
                originalRuleset = mixin.originalRuleset || mixin;
                mixin = new MixinDefinition("", [], mixin.rules, null, false, null, originalRuleset.visibilityInfo());
                mixin.originalRuleset = originalRuleset;
              }
              var newRules = mixin.evalCall(context, args, this.important).rules;
              this._setVisibilityToReplacement(newRules);
              Array.prototype.push.apply(rules, newRules);
            } catch (e) {
              throw { message: e.message, index: this.index, filename: this.currentFileInfo.filename, stack: e.stack };
            }
          }
        }

        if (match) {
          return rules;
        }
      }
    }
    if (isOneFound) {
      throw { type:    'Runtime',
        message: 'No matching definition was found for `' + this.format(args) + '`',
        index:   this.index, filename: this.currentFileInfo.filename };
    } else {
      throw { type:    'Name',
        message: this.selector.toCSS().trim() + " is undefined",
        index:   this.index, filename: this.currentFileInfo.filename };
    }
  };

  MixinCall.prototype._setVisibilityToReplacement = function (replacement) {
    var i, rule;
    if (this.blocksVisibility()) {
      for (i = 0; i < replacement.length; i++) {
        rule = replacement[i];
        rule.addVisibilityBlock();
      }
    }
  };
  MixinCall.prototype.format = function (args) {
    return this.selector.toCSS().trim() + '(' +
      (args ? args.map(function (a) {
        var argValue = "";
        if (a.name) {
          argValue += a.name + ":";
        }
        if (a.value.toCSS) {
          argValue += a.value.toCSS();
        } else {
          argValue += "???";
        }
        return argValue;
      }).join(', ') : "") + ")";
  };
  module.exports = MixinCall;

},{"../functions/default":20,"./mixin-definition":68,"./node":70,"./selector":77}],68:[function(require,module,exports){
  var Selector = require("./selector"),
    Element = require("./element"),
    Ruleset = require("./ruleset"),
    Rule = require("./rule"),
    Expression = require("./expression"),
    contexts = require("../contexts");

  var Definition = function (name, params, rules, condition, variadic, frames, visibilityInfo) {
    this.name = name;
    this.selectors = [new Selector([new Element(null, name, this.index, this.currentFileInfo)])];
    this.params = params;
    this.condition = condition;
    this.variadic = variadic;
    this.arity = params.length;
    this.rules = rules;
    this._lookups = {};
    var optionalParameters = [];
    this.required = params.reduce(function (count, p) {
      if (!p.name || (p.name && !p.value)) {
        return count + 1;
      }
      else {
        optionalParameters.push(p.name);
        return count;
      }
    }, 0);
    this.optionalParameters = optionalParameters;
    this.frames = frames;
    this.copyVisibilityInfo(visibilityInfo);
    this.allowRoot = true;
  };
  Definition.prototype = new Ruleset();
  Definition.prototype.type = "MixinDefinition";
  Definition.prototype.evalFirst = true;
  Definition.prototype.accept = function (visitor) {
    if (this.params && this.params.length) {
      this.params = visitor.visitArray(this.params);
    }
    this.rules = visitor.visitArray(this.rules);
    if (this.condition) {
      this.condition = visitor.visit(this.condition);
    }
  };
  Definition.prototype.evalParams = function (context, mixinEnv, args, evaldArguments) {
    /*jshint boss:true */
    var frame = new Ruleset(null, null),
      varargs, arg,
      params = this.params.slice(0),
      i, j, val, name, isNamedFound, argIndex, argsLength = 0;

    if (mixinEnv.frames && mixinEnv.frames[0] && mixinEnv.frames[0].functionRegistry) {
      frame.functionRegistry = mixinEnv.frames[0].functionRegistry.inherit();
    }
    mixinEnv = new contexts.Eval(mixinEnv, [frame].concat(mixinEnv.frames));

    if (args) {
      args = args.slice(0);
      argsLength = args.length;

      for (i = 0; i < argsLength; i++) {
        arg = args[i];
        if (name = (arg && arg.name)) {
          isNamedFound = false;
          for (j = 0; j < params.length; j++) {
            if (!evaldArguments[j] && name === params[j].name) {
              evaldArguments[j] = arg.value.eval(context);
              frame.prependRule(new Rule(name, arg.value.eval(context)));
              isNamedFound = true;
              break;
            }
          }
          if (isNamedFound) {
            args.splice(i, 1);
            i--;
            continue;
          } else {
            throw { type: 'Runtime', message: "Named argument for " + this.name +
            ' ' + args[i].name + ' not found' };
          }
        }
      }
    }
    argIndex = 0;
    for (i = 0; i < params.length; i++) {
      if (evaldArguments[i]) { continue; }

      arg = args && args[argIndex];

      if (name = params[i].name) {
        if (params[i].variadic) {
          varargs = [];
          for (j = argIndex; j < argsLength; j++) {
            varargs.push(args[j].value.eval(context));
          }
          frame.prependRule(new Rule(name, new Expression(varargs).eval(context)));
        } else {
          val = arg && arg.value;
          if (val) {
            val = val.eval(context);
          } else if (params[i].value) {
            val = params[i].value.eval(mixinEnv);
            frame.resetCache();
          } else {
            throw { type: 'Runtime', message: "wrong number of arguments for " + this.name +
            ' (' + argsLength + ' for ' + this.arity + ')' };
          }

          frame.prependRule(new Rule(name, val));
          evaldArguments[i] = val;
        }
      }

      if (params[i].variadic && args) {
        for (j = argIndex; j < argsLength; j++) {
          evaldArguments[j] = args[j].value.eval(context);
        }
      }
      argIndex++;
    }

    return frame;
  };
  Definition.prototype.makeImportant = function() {
    var rules = !this.rules ? this.rules : this.rules.map(function (r) {
      if (r.makeImportant) {
        return r.makeImportant(true);
      } else {
        return r;
      }
    });
    var result = new Definition(this.name, this.params, rules, this.condition, this.variadic, this.frames);
    return result;
  };
  Definition.prototype.eval = function (context) {
    return new Definition(this.name, this.params, this.rules, this.condition, this.variadic, this.frames || context.frames.slice(0));
  };
  Definition.prototype.evalCall = function (context, args, important) {
    var _arguments = [],
      mixinFrames = this.frames ? this.frames.concat(context.frames) : context.frames,
      frame = this.evalParams(context, new contexts.Eval(context, mixinFrames), args, _arguments),
      rules, ruleset;

    frame.prependRule(new Rule('@arguments', new Expression(_arguments).eval(context)));

    rules = this.rules.slice(0);

    ruleset = new Ruleset(null, rules);
    ruleset.originalRuleset = this;
    ruleset = ruleset.eval(new contexts.Eval(context, [this, frame].concat(mixinFrames)));
    if (important) {
      ruleset = ruleset.makeImportant();
    }
    return ruleset;
  };
  Definition.prototype.matchCondition = function (args, context) {
    if (this.condition && !this.condition.eval(
        new contexts.Eval(context,
          [this.evalParams(context, /* the parameter variables*/
            new contexts.Eval(context, this.frames ? this.frames.concat(context.frames) : context.frames), args, [])]
            .concat(this.frames || []) // the parent namespace/mixin frames
            .concat(context.frames)))) { // the current environment frames
      return false;
    }
    return true;
  };
  Definition.prototype.matchArgs = function (args, context) {
    var allArgsCnt = (args && args.length) || 0, len, optionalParameters = this.optionalParameters;
    var requiredArgsCnt = !args ? 0 : args.reduce(function (count, p) {
      if (optionalParameters.indexOf(p.name) < 0) {
        return count + 1;
      } else {
        return count;
      }
    }, 0);

    if (! this.variadic) {
      if (requiredArgsCnt < this.required) {
        return false;
      }
      if (allArgsCnt > this.params.length) {
        return false;
      }
    } else {
      if (requiredArgsCnt < (this.required - 1)) {
        return false;
      }
    }

    // check patterns
    len = Math.min(requiredArgsCnt, this.arity);

    for (var i = 0; i < len; i++) {
      if (!this.params[i].name && !this.params[i].variadic) {
        if (args[i].value.eval(context).toCSS() != this.params[i].value.eval(context).toCSS()) {
          return false;
        }
      }
    }
    return true;
  };
  module.exports = Definition;

},{"../contexts":11,"./element":58,"./expression":59,"./rule":74,"./ruleset":76,"./selector":77}],69:[function(require,module,exports){
  var Node = require("./node"),
    Operation = require("./operation"),
    Dimension = require("./dimension");

  var Negative = function (node) {
    this.value = node;
  };
  Negative.prototype = new Node();
  Negative.prototype.type = "Negative";
  Negative.prototype.genCSS = function (context, output) {
    output.add('-');
    this.value.genCSS(context, output);
  };
  Negative.prototype.eval = function (context) {
    if (context.isMathOn()) {
      return (new Operation('*', [new Dimension(-1), this.value])).eval(context);
    }
    return new Negative(this.value.eval(context));
  };
  module.exports = Negative;

},{"./dimension":56,"./node":70,"./operation":71}],70:[function(require,module,exports){
  var Node = function() {
  };
  Node.prototype.toCSS = function (context) {
    var strs = [];
    this.genCSS(context, {
      add: function(chunk, fileInfo, index) {
        strs.push(chunk);
      },
      isEmpty: function () {
        return strs.length === 0;
      }
    });
    return strs.join('');
  };
  Node.prototype.genCSS = function (context, output) {
    output.add(this.value);
  };
  Node.prototype.accept = function (visitor) {
    this.value = visitor.visit(this.value);
  };
  Node.prototype.eval = function () { return this; };
  Node.prototype._operate = function (context, op, a, b) {
    switch (op) {
      case '+': return a + b;
      case '-': return a - b;
      case '*': return a * b;
      case '/': return a / b;
    }
  };
  Node.prototype.fround = function(context, value) {
    var precision = context && context.numPrecision;
    //add "epsilon" to ensure numbers like 1.000000005 (represented as 1.000000004999....) are properly rounded...
    return (precision == null) ? value : Number((value + 2e-16).toFixed(precision));
  };
  Node.compare = function (a, b) {
    /* returns:
     -1: a < b
     0: a = b
     1: a > b
     and *any* other value for a != b (e.g. undefined, NaN, -2 etc.) */

    if ((a.compare) &&
      // for "symmetric results" force toCSS-based comparison
      // of Quoted or Anonymous if either value is one of those
      !(b.type === "Quoted" || b.type === "Anonymous")) {
      return a.compare(b);
    } else if (b.compare) {
      return -b.compare(a);
    } else if (a.type !== b.type) {
      return undefined;
    }

    a = a.value;
    b = b.value;
    if (!Array.isArray(a)) {
      return a === b ? 0 : undefined;
    }
    if (a.length !== b.length) {
      return undefined;
    }
    for (var i = 0; i < a.length; i++) {
      if (Node.compare(a[i], b[i]) !== 0) {
        return undefined;
      }
    }
    return 0;
  };

  Node.numericCompare = function (a, b) {
    return a  <  b ? -1
      : a === b ?  0
        : a  >  b ?  1 : undefined;
  };
// Returns true if this node represents root of ast imported by reference
  Node.prototype.blocksVisibility = function () {
    if (this.visibilityBlocks == null) {
      this.visibilityBlocks = 0;
    }
    return this.visibilityBlocks !== 0;
  };
  Node.prototype.addVisibilityBlock = function () {
    if (this.visibilityBlocks == null) {
      this.visibilityBlocks = 0;
    }
    this.visibilityBlocks = this.visibilityBlocks + 1;
  };
  Node.prototype.removeVisibilityBlock = function () {
    if (this.visibilityBlocks == null) {
      this.visibilityBlocks = 0;
    }
    this.visibilityBlocks = this.visibilityBlocks - 1;
  };
//Turns on node visibility - if called node will be shown in output regardless
//of whether it comes from import by reference or not
  Node.prototype.ensureVisibility = function () {
    this.nodeVisible = true;
  };
//Turns off node visibility - if called node will NOT be shown in output regardless
//of whether it comes from import by reference or not
  Node.prototype.ensureInvisibility = function () {
    this.nodeVisible = false;
  };
// return values:
// false - the node must not be visible
// true - the node must be visible
// undefined or null - the node has the same visibility as its parent
  Node.prototype.isVisible = function () {
    return this.nodeVisible;
  };
  Node.prototype.visibilityInfo = function() {
    return {
      visibilityBlocks: this.visibilityBlocks,
      nodeVisible: this.nodeVisible
    };
  };
  Node.prototype.copyVisibilityInfo = function(info) {
    if (!info) {
      return;
    }
    this.visibilityBlocks = info.visibilityBlocks;
    this.nodeVisible = info.nodeVisible;
  };
  module.exports = Node;

},{}],71:[function(require,module,exports){
  var Node = require("./node"),
    Color = require("./color"),
    Dimension = require("./dimension");

  var Operation = function (op, operands, isSpaced) {
    this.op = op.trim();
    this.operands = operands;
    this.isSpaced = isSpaced;
  };
  Operation.prototype = new Node();
  Operation.prototype.type = "Operation";
  Operation.prototype.accept = function (visitor) {
    this.operands = visitor.visit(this.operands);
  };
  Operation.prototype.eval = function (context) {
    var a = this.operands[0].eval(context),
      b = this.operands[1].eval(context);

    if (context.isMathOn()) {
      if (a instanceof Dimension && b instanceof Color) {
        a = a.toColor();
      }
      if (b instanceof Dimension && a instanceof Color) {
        b = b.toColor();
      }
      if (!a.operate) {
        throw { type: "Operation",
          message: "Operation on an invalid type" };
      }

      return a.operate(context, this.op, b);
    } else {
      return new Operation(this.op, [a, b], this.isSpaced);
    }
  };
  Operation.prototype.genCSS = function (context, output) {
    this.operands[0].genCSS(context, output);
    if (this.isSpaced) {
      output.add(" ");
    }
    output.add(this.op);
    if (this.isSpaced) {
      output.add(" ");
    }
    this.operands[1].genCSS(context, output);
  };

  module.exports = Operation;

},{"./color":50,"./dimension":56,"./node":70}],72:[function(require,module,exports){
  var Node = require("./node");

  var Paren = function (node) {
    this.value = node;
  };
  Paren.prototype = new Node();
  Paren.prototype.type = "Paren";
  Paren.prototype.genCSS = function (context, output) {
    output.add('(');
    this.value.genCSS(context, output);
    output.add(')');
  };
  Paren.prototype.eval = function (context) {
    return new Paren(this.value.eval(context));
  };
  module.exports = Paren;

},{"./node":70}],73:[function(require,module,exports){
  var Node = require("./node"),
    JsEvalNode = require("./js-eval-node"),
    Variable = require("./variable");

  var Quoted = function (str, content, escaped, index, currentFileInfo) {
    this.escaped = (escaped == null) ? true : escaped;
    this.value = content || '';
    this.quote = str.charAt(0);
    this.index = index;
    this.currentFileInfo = currentFileInfo;
  };
  Quoted.prototype = new JsEvalNode();
  Quoted.prototype.type = "Quoted";
  Quoted.prototype.genCSS = function (context, output) {
    if (!this.escaped) {
      output.add(this.quote, this.currentFileInfo, this.index);
    }
    output.add(this.value);
    if (!this.escaped) {
      output.add(this.quote);
    }
  };
  Quoted.prototype.containsVariables = function() {
    return this.value.match(/(`([^`]+)`)|@\{([\w-]+)\}/);
  };
  Quoted.prototype.eval = function (context) {
    var that = this, value = this.value;
    var javascriptReplacement = function (_, exp) {
      return String(that.evaluateJavaScript(exp, context));
    };
    var interpolationReplacement = function (_, name) {
      var v = new Variable('@' + name, that.index, that.currentFileInfo).eval(context, true);
      return (v instanceof Quoted) ? v.value : v.toCSS();
    };
    function iterativeReplace(value, regexp, replacementFnc) {
      var evaluatedValue = value;
      do {
        value = evaluatedValue;
        evaluatedValue = value.replace(regexp, replacementFnc);
      } while (value !== evaluatedValue);
      return evaluatedValue;
    }
    value = iterativeReplace(value, /`([^`]+)`/g, javascriptReplacement);
    value = iterativeReplace(value, /@\{([\w-]+)\}/g, interpolationReplacement);
    return new Quoted(this.quote + value + this.quote, value, this.escaped, this.index, this.currentFileInfo);
  };
  Quoted.prototype.compare = function (other) {
    // when comparing quoted strings allow the quote to differ
    if (other.type === "Quoted" && !this.escaped && !other.escaped) {
      return Node.numericCompare(this.value, other.value);
    } else {
      return other.toCSS && this.toCSS() === other.toCSS() ? 0 : undefined;
    }
  };
  module.exports = Quoted;

},{"./js-eval-node":64,"./node":70,"./variable":82}],74:[function(require,module,exports){
  var Node = require("./node"),
    Value = require("./value"),
    Keyword = require("./keyword");

  var Rule = function (name, value, important, merge, index, currentFileInfo, inline, variable) {
    this.name = name;
    this.value = (value instanceof Node) ? value : new Value([value]); //value instanceof tree.Value || value instanceof tree.Ruleset ??
    this.important = important ? ' ' + important.trim() : '';
    this.merge = merge;
    this.index = index;
    this.currentFileInfo = currentFileInfo;
    this.inline = inline || false;
    this.variable = (variable !== undefined) ? variable
      : (name.charAt && (name.charAt(0) === '@'));
    this.allowRoot = true;
  };

  function evalName(context, name) {
    var value = "", i, n = name.length,
      output = {add: function (s) {value += s;}};
    for (i = 0; i < n; i++) {
      name[i].eval(context).genCSS(context, output);
    }
    return value;
  }

  Rule.prototype = new Node();
  Rule.prototype.type = "Rule";
  Rule.prototype.genCSS = function (context, output) {
    output.add(this.name + (context.compress ? ':' : ': '), this.currentFileInfo, this.index);
    try {
      this.value.genCSS(context, output);
    }
    catch(e) {
      e.index = this.index;
      e.filename = this.currentFileInfo.filename;
      throw e;
    }
    output.add(this.important + ((this.inline || (context.lastRule && context.compress)) ? "" : ";"), this.currentFileInfo, this.index);
  };
  Rule.prototype.eval = function (context) {
    var strictMathBypass = false, name = this.name, evaldValue, variable = this.variable;
    if (typeof name !== "string") {
      // expand 'primitive' name directly to get
      // things faster (~10% for benchmark.less):
      name = (name.length === 1) && (name[0] instanceof Keyword) ?
        name[0].value : evalName(context, name);
      variable = false; // never treat expanded interpolation as new variable name
    }
    if (name === "font" && !context.strictMath) {
      strictMathBypass = true;
      context.strictMath = true;
    }
    try {
      context.importantScope.push({});
      evaldValue = this.value.eval(context);

      if (!this.variable && evaldValue.type === "DetachedRuleset") {
        throw { message: "Rulesets cannot be evaluated on a property.",
          index: this.index, filename: this.currentFileInfo.filename };
      }
      var important = this.important,
        importantResult = context.importantScope.pop();
      if (!important && importantResult.important) {
        important = importantResult.important;
      }

      return new Rule(name,
        evaldValue,
        important,
        this.merge,
        this.index, this.currentFileInfo, this.inline,
        variable);
    }
    catch(e) {
      if (typeof e.index !== 'number') {
        e.index = this.index;
        e.filename = this.currentFileInfo.filename;
      }
      throw e;
    }
    finally {
      if (strictMathBypass) {
        context.strictMath = false;
      }
    }
  };
  Rule.prototype.makeImportant = function () {
    return new Rule(this.name,
      this.value,
      "!important",
      this.merge,
      this.index, this.currentFileInfo, this.inline);
  };

  module.exports = Rule;
},{"./keyword":65,"./node":70,"./value":81}],75:[function(require,module,exports){
  var Node = require("./node"),
    Variable = require("./variable");

  var RulesetCall = function (variable) {
    this.variable = variable;
    this.allowRoot = true;
  };
  RulesetCall.prototype = new Node();
  RulesetCall.prototype.type = "RulesetCall";
  RulesetCall.prototype.eval = function (context) {
    var detachedRuleset = new Variable(this.variable).eval(context);
    return detachedRuleset.callEval(context);
  };
  module.exports = RulesetCall;

},{"./node":70,"./variable":82}],76:[function(require,module,exports){
  var Node = require("./node"),
    Rule = require("./rule"),
    Selector = require("./selector"),
    Element = require("./element"),
    Paren = require("./paren"),
    contexts = require("../contexts"),
    globalFunctionRegistry = require("../functions/function-registry"),
    defaultFunc = require("../functions/default"),
    getDebugInfo = require("./debug-info");

  var Ruleset = function (selectors, rules, strictImports, visibilityInfo) {
    this.selectors = selectors;
    this.rules = rules;
    this._lookups = {};
    this.strictImports = strictImports;
    this.copyVisibilityInfo(visibilityInfo);
    this.allowRoot = true;
  };
  Ruleset.prototype = new Node();
  Ruleset.prototype.type = "Ruleset";
  Ruleset.prototype.isRuleset = true;
  Ruleset.prototype.isRulesetLike = true;
  Ruleset.prototype.accept = function (visitor) {
    if (this.paths) {
      this.paths = visitor.visitArray(this.paths, true);
    } else if (this.selectors) {
      this.selectors = visitor.visitArray(this.selectors);
    }
    if (this.rules && this.rules.length) {
      this.rules = visitor.visitArray(this.rules);
    }
  };
  Ruleset.prototype.eval = function (context) {
    var thisSelectors = this.selectors, selectors,
      selCnt, selector, i, hasOnePassingSelector = false;

    if (thisSelectors && (selCnt = thisSelectors.length)) {
      selectors = [];
      defaultFunc.error({
        type: "Syntax",
        message: "it is currently only allowed in parametric mixin guards,"
      });
      for (i = 0; i < selCnt; i++) {
        selector = thisSelectors[i].eval(context);
        selectors.push(selector);
        if (selector.evaldCondition) {
          hasOnePassingSelector = true;
        }
      }
      defaultFunc.reset();
    } else {
      hasOnePassingSelector = true;
    }

    var rules = this.rules ? this.rules.slice(0) : null,
      ruleset = new Ruleset(selectors, rules, this.strictImports, this.visibilityInfo()),
      rule, subRule;

    ruleset.originalRuleset = this;
    ruleset.root = this.root;
    ruleset.firstRoot = this.firstRoot;
    ruleset.allowImports = this.allowImports;

    if (this.debugInfo) {
      ruleset.debugInfo = this.debugInfo;
    }

    if (!hasOnePassingSelector) {
      rules.length = 0;
    }

    // inherit a function registry from the frames stack when possible;
    // otherwise from the global registry
    ruleset.functionRegistry = (function (frames) {
      var i = 0,
        n = frames.length,
        found;
      for ( ; i !== n ; ++i ) {
        found = frames[ i ].functionRegistry;
        if ( found ) { return found; }
      }
      return globalFunctionRegistry;
    }(context.frames)).inherit();

    // push the current ruleset to the frames stack
    var ctxFrames = context.frames;
    ctxFrames.unshift(ruleset);

    // currrent selectors
    var ctxSelectors = context.selectors;
    if (!ctxSelectors) {
      context.selectors = ctxSelectors = [];
    }
    ctxSelectors.unshift(this.selectors);

    // Evaluate imports
    if (ruleset.root || ruleset.allowImports || !ruleset.strictImports) {
      ruleset.evalImports(context);
    }

    // Store the frames around mixin definitions,
    // so they can be evaluated like closures when the time comes.
    var rsRules = ruleset.rules, rsRuleCnt = rsRules ? rsRules.length : 0;
    for (i = 0; i < rsRuleCnt; i++) {
      if (rsRules[i].evalFirst) {
        rsRules[i] = rsRules[i].eval(context);
      }
    }

    var mediaBlockCount = (context.mediaBlocks && context.mediaBlocks.length) || 0;

    // Evaluate mixin calls.
    for (i = 0; i < rsRuleCnt; i++) {
      if (rsRules[i].type === "MixinCall") {
        /*jshint loopfunc:true */
        rules = rsRules[i].eval(context).filter(function(r) {
          if ((r instanceof Rule) && r.variable) {
            // do not pollute the scope if the variable is
            // already there. consider returning false here
            // but we need a way to "return" variable from mixins
            return !(ruleset.variable(r.name));
          }
          return true;
        });
        rsRules.splice.apply(rsRules, [i, 1].concat(rules));
        rsRuleCnt += rules.length - 1;
        i += rules.length - 1;
        ruleset.resetCache();
      } else if (rsRules[i].type === "RulesetCall") {
        /*jshint loopfunc:true */
        rules = rsRules[i].eval(context).rules.filter(function(r) {
          if ((r instanceof Rule) && r.variable) {
            // do not pollute the scope at all
            return false;
          }
          return true;
        });
        rsRules.splice.apply(rsRules, [i, 1].concat(rules));
        rsRuleCnt += rules.length - 1;
        i += rules.length - 1;
        ruleset.resetCache();
      }
    }

    // Evaluate everything else
    for (i = 0; i < rsRules.length; i++) {
      rule = rsRules[i];
      if (!rule.evalFirst) {
        rsRules[i] = rule = rule.eval ? rule.eval(context) : rule;
      }
    }

    // Evaluate everything else
    for (i = 0; i < rsRules.length; i++) {
      rule = rsRules[i];
      // for rulesets, check if it is a css guard and can be removed
      if (rule instanceof Ruleset && rule.selectors && rule.selectors.length === 1) {
        // check if it can be folded in (e.g. & where)
        if (rule.selectors[0].isJustParentSelector()) {
          rsRules.splice(i--, 1);

          for (var j = 0; j < rule.rules.length; j++) {
            subRule = rule.rules[j];
            subRule.copyVisibilityInfo(rule.visibilityInfo());
            if (!(subRule instanceof Rule) || !subRule.variable) {
              rsRules.splice(++i, 0, subRule);
            }
          }
        }
      }
    }

    // Pop the stack
    ctxFrames.shift();
    ctxSelectors.shift();

    if (context.mediaBlocks) {
      for (i = mediaBlockCount; i < context.mediaBlocks.length; i++) {
        context.mediaBlocks[i].bubbleSelectors(selectors);
      }
    }

    return ruleset;
  };
  Ruleset.prototype.evalImports = function(context) {
    var rules = this.rules, i, importRules;
    if (!rules) { return; }

    for (i = 0; i < rules.length; i++) {
      if (rules[i].type === "Import") {
        importRules = rules[i].eval(context);
        if (importRules && (importRules.length || importRules.length === 0)) {
          rules.splice.apply(rules, [i, 1].concat(importRules));
          i+= importRules.length - 1;
        } else {
          rules.splice(i, 1, importRules);
        }
        this.resetCache();
      }
    }
  };
  Ruleset.prototype.makeImportant = function() {
    var result = new Ruleset(this.selectors, this.rules.map(function (r) {
      if (r.makeImportant) {
        return r.makeImportant();
      } else {
        return r;
      }
    }), this.strictImports, this.visibilityInfo());

    return result;
  };
  Ruleset.prototype.matchArgs = function (args) {
    return !args || args.length === 0;
  };
// lets you call a css selector with a guard
  Ruleset.prototype.matchCondition = function (args, context) {
    var lastSelector = this.selectors[this.selectors.length - 1];
    if (!lastSelector.evaldCondition) {
      return false;
    }
    if (lastSelector.condition &&
      !lastSelector.condition.eval(
        new contexts.Eval(context,
          context.frames))) {
      return false;
    }
    return true;
  };
  Ruleset.prototype.resetCache = function () {
    this._rulesets = null;
    this._variables = null;
    this._lookups = {};
  };
  Ruleset.prototype.variables = function () {
    if (!this._variables) {
      this._variables = !this.rules ? {} : this.rules.reduce(function (hash, r) {
        if (r instanceof Rule && r.variable === true) {
          hash[r.name] = r;
        }
        // when evaluating variables in an import statement, imports have not been eval'd
        // so we need to go inside import statements.
        // guard against root being a string (in the case of inlined less)
        if (r.type === "Import" && r.root && r.root.variables) {
          var vars = r.root.variables();
          for (var name in vars) {
            if (vars.hasOwnProperty(name)) {
              hash[name] = vars[name];
            }
          }
        }
        return hash;
      }, {});
    }
    return this._variables;
  };
  Ruleset.prototype.variable = function (name) {
    return this.variables()[name];
  };
  Ruleset.prototype.rulesets = function () {
    if (!this.rules) { return []; }

    var filtRules = [], rules = this.rules, cnt = rules.length,
      i, rule;

    for (i = 0; i < cnt; i++) {
      rule = rules[i];
      if (rule.isRuleset) {
        filtRules.push(rule);
      }
    }

    return filtRules;
  };
  Ruleset.prototype.prependRule = function (rule) {
    var rules = this.rules;
    if (rules) {
      rules.unshift(rule);
    } else {
      this.rules = [ rule ];
    }
  };
  Ruleset.prototype.find = function (selector, self, filter) {
    self = self || this;
    var rules = [], match, foundMixins,
      key = selector.toCSS();

    if (key in this._lookups) { return this._lookups[key]; }

    this.rulesets().forEach(function (rule) {
      if (rule !== self) {
        for (var j = 0; j < rule.selectors.length; j++) {
          match = selector.match(rule.selectors[j]);
          if (match) {
            if (selector.elements.length > match) {
              if (!filter || filter(rule)) {
                foundMixins = rule.find(new Selector(selector.elements.slice(match)), self, filter);
                for (var i = 0; i < foundMixins.length; ++i) {
                  foundMixins[i].path.push(rule);
                }
                Array.prototype.push.apply(rules, foundMixins);
              }
            } else {
              rules.push({ rule: rule, path: []});
            }
            break;
          }
        }
      }
    });
    this._lookups[key] = rules;
    return rules;
  };
  Ruleset.prototype.genCSS = function (context, output) {
    var i, j,
      charsetRuleNodes = [],
      ruleNodes = [],
      debugInfo,     // Line number debugging
      rule,
      path;

    context.tabLevel = (context.tabLevel || 0);

    if (!this.root) {
      context.tabLevel++;
    }

    var tabRuleStr = context.compress ? '' : Array(context.tabLevel + 1).join("  "),
      tabSetStr = context.compress ? '' : Array(context.tabLevel).join("  "),
      sep;

    function isRulesetLikeNode(rule) {
      // if it has nested rules, then it should be treated like a ruleset
      // medias and comments do not have nested rules, but should be treated like rulesets anyway
      // some directives and anonymous nodes are ruleset like, others are not
      if (typeof rule.isRulesetLike === "boolean") {
        return rule.isRulesetLike;
      } else if (typeof rule.isRulesetLike === "function") {
        return rule.isRulesetLike();
      }

      //anything else is assumed to be a rule
      return false;
    }

    var charsetNodeIndex = 0;
    var importNodeIndex = 0;
    for (i = 0; i < this.rules.length; i++) {
      rule = this.rules[i];
      if (rule.type === "Comment") {
        if (importNodeIndex === i) {
          importNodeIndex++;
        }
        ruleNodes.push(rule);
      } else if (rule.isCharset && rule.isCharset()) {
        ruleNodes.splice(charsetNodeIndex, 0, rule);
        charsetNodeIndex++;
        importNodeIndex++;
      } else if (rule.type === "Import") {
        ruleNodes.splice(importNodeIndex, 0, rule);
        importNodeIndex++;
      } else {
        ruleNodes.push(rule);
      }
    }
    ruleNodes = charsetRuleNodes.concat(ruleNodes);

    // If this is the root node, we don't render
    // a selector, or {}.
    if (!this.root) {
      debugInfo = getDebugInfo(context, this, tabSetStr);

      if (debugInfo) {
        output.add(debugInfo);
        output.add(tabSetStr);
      }

      var paths = this.paths, pathCnt = paths.length,
        pathSubCnt;

      sep = context.compress ? ',' : (',\n' + tabSetStr);

      for (i = 0; i < pathCnt; i++) {
        path = paths[i];
        if (!(pathSubCnt = path.length)) { continue; }
        if (i > 0) { output.add(sep); }

        context.firstSelector = true;
        path[0].genCSS(context, output);

        context.firstSelector = false;
        for (j = 1; j < pathSubCnt; j++) {
          path[j].genCSS(context, output);
        }
      }

      output.add((context.compress ? '{' : ' {\n') + tabRuleStr);
    }

    // Compile rules and rulesets
    for (i = 0; i < ruleNodes.length; i++) {
      rule = ruleNodes[i];

      if (i + 1 === ruleNodes.length) {
        context.lastRule = true;
      }

      var currentLastRule = context.lastRule;
      if (isRulesetLikeNode(rule)) {
        context.lastRule = false;
      }

      if (rule.genCSS) {
        rule.genCSS(context, output);
      } else if (rule.value) {
        output.add(rule.value.toString());
      }

      context.lastRule = currentLastRule;

      if (!context.lastRule) {
        output.add(context.compress ? '' : ('\n' + tabRuleStr));
      } else {
        context.lastRule = false;
      }
    }

    if (!this.root) {
      output.add((context.compress ? '}' : '\n' + tabSetStr + '}'));
      context.tabLevel--;
    }

    if (!output.isEmpty() && !context.compress && this.firstRoot) {
      output.add('\n');
    }
  };

  Ruleset.prototype.joinSelectors = function (paths, context, selectors) {
    for (var s = 0; s < selectors.length; s++) {
      this.joinSelector(paths, context, selectors[s]);
    }
  };

  Ruleset.prototype.joinSelector = function (paths, context, selector) {

    function createParenthesis(elementsToPak, originalElement) {
      var replacementParen, j;
      if (elementsToPak.length === 0) {
        replacementParen = new Paren(elementsToPak[0]);
      } else {
        var insideParent = [];
        for (j = 0; j < elementsToPak.length; j++) {
          insideParent.push(new Element(null, elementsToPak[j], originalElement.index, originalElement.currentFileInfo));
        }
        replacementParen = new Paren(new Selector(insideParent));
      }
      return replacementParen;
    }

    function createSelector(containedElement, originalElement) {
      var element, selector;
      element = new Element(null, containedElement, originalElement.index, originalElement.currentFileInfo);
      selector = new Selector([element]);
      return selector;
    }

    // joins selector path from `beginningPath` with selector path in `addPath`
    // `replacedElement` contains element that is being replaced by `addPath`
    // returns concatenated path
    function addReplacementIntoPath(beginningPath, addPath, replacedElement, originalSelector) {
      var newSelectorPath, lastSelector, newJoinedSelector;
      // our new selector path
      newSelectorPath = [];

      //construct the joined selector - if & is the first thing this will be empty,
      // if not newJoinedSelector will be the last set of elements in the selector
      if (beginningPath.length > 0) {
        newSelectorPath = beginningPath.slice(0);
        lastSelector = newSelectorPath.pop();
        newJoinedSelector = originalSelector.createDerived(lastSelector.elements.slice(0));
      }
      else {
        newJoinedSelector = originalSelector.createDerived([]);
      }

      if (addPath.length > 0) {
        // /deep/ is a combinator that is valid without anything in front of it
        // so if the & does not have a combinator that is "" or " " then
        // and there is a combinator on the parent, then grab that.
        // this also allows + a { & .b { .a & { ... though not sure why you would want to do that
        var combinator = replacedElement.combinator, parentEl = addPath[0].elements[0];
        if (combinator.emptyOrWhitespace && !parentEl.combinator.emptyOrWhitespace) {
          combinator = parentEl.combinator;
        }
        // join the elements so far with the first part of the parent
        newJoinedSelector.elements.push(new Element(combinator, parentEl.value, replacedElement.index, replacedElement.currentFileInfo));
        newJoinedSelector.elements = newJoinedSelector.elements.concat(addPath[0].elements.slice(1));
      }

      // now add the joined selector - but only if it is not empty
      if (newJoinedSelector.elements.length !== 0) {
        newSelectorPath.push(newJoinedSelector);
      }

      //put together the parent selectors after the join (e.g. the rest of the parent)
      if (addPath.length > 1) {
        var restOfPath = addPath.slice(1);
        restOfPath = restOfPath.map(function (selector) {
          return selector.createDerived(selector.elements, []);
        });
        newSelectorPath = newSelectorPath.concat(restOfPath);
      }
      return newSelectorPath;
    }

    // joins selector path from `beginningPath` with every selector path in `addPaths` array
    // `replacedElement` contains element that is being replaced by `addPath`
    // returns array with all concatenated paths
    function addAllReplacementsIntoPath( beginningPath, addPaths, replacedElement, originalSelector, result) {
      var j;
      for (j = 0; j < beginningPath.length; j++) {
        var newSelectorPath = addReplacementIntoPath(beginningPath[j], addPaths, replacedElement, originalSelector);
        result.push(newSelectorPath);
      }
      return result;
    }

    function mergeElementsOnToSelectors(elements, selectors) {
      var i, sel;

      if (elements.length === 0) {
        return ;
      }
      if (selectors.length === 0) {
        selectors.push([ new Selector(elements) ]);
        return;
      }

      for (i = 0; i < selectors.length; i++) {
        sel = selectors[i];

        // if the previous thing in sel is a parent this needs to join on to it
        if (sel.length > 0) {
          sel[sel.length - 1] = sel[sel.length - 1].createDerived(sel[sel.length - 1].elements.concat(elements));
        }
        else {
          sel.push(new Selector(elements));
        }
      }
    }

    // replace all parent selectors inside `inSelector` by content of `context` array
    // resulting selectors are returned inside `paths` array
    // returns true if `inSelector` contained at least one parent selector
    function replaceParentSelector(paths, context, inSelector) {
      // The paths are [[Selector]]
      // The first list is a list of comma separated selectors
      // The inner list is a list of inheritance separated selectors
      // e.g.
      // .a, .b {
      //   .c {
      //   }
      // }
      // == [[.a] [.c]] [[.b] [.c]]
      //
      var i, j, k, currentElements, newSelectors, selectorsMultiplied, sel, el, hadParentSelector = false, length, lastSelector;
      function findNestedSelector(element) {
        var maybeSelector;
        if (element.value.type !== 'Paren') {
          return null;
        }

        maybeSelector = element.value.value;
        if (maybeSelector.type !== 'Selector') {
          return null;
        }

        return maybeSelector;
      }

      // the elements from the current selector so far
      currentElements = [];
      // the current list of new selectors to add to the path.
      // We will build it up. We initiate it with one empty selector as we "multiply" the new selectors
      // by the parents
      newSelectors = [
        []
      ];

      for (i = 0; i < inSelector.elements.length; i++) {
        el = inSelector.elements[i];
        // non parent reference elements just get added
        if (el.value !== "&") {
          var nestedSelector = findNestedSelector(el);
          if (nestedSelector != null) {
            // merge the current list of non parent selector elements
            // on to the current list of selectors to add
            mergeElementsOnToSelectors(currentElements, newSelectors);

            var nestedPaths = [], replaced, replacedNewSelectors = [];
            replaced = replaceParentSelector(nestedPaths, context, nestedSelector);
            hadParentSelector = hadParentSelector || replaced;
            //the nestedPaths array should have only one member - replaceParentSelector does not multiply selectors
            for (k = 0; k < nestedPaths.length; k++) {
              var replacementSelector = createSelector(createParenthesis(nestedPaths[k], el), el);
              addAllReplacementsIntoPath(newSelectors, [replacementSelector], el, inSelector, replacedNewSelectors);
            }
            newSelectors = replacedNewSelectors;
            currentElements = [];

          } else {
            currentElements.push(el);
          }

        } else {
          hadParentSelector = true;
          // the new list of selectors to add
          selectorsMultiplied = [];

          // merge the current list of non parent selector elements
          // on to the current list of selectors to add
          mergeElementsOnToSelectors(currentElements, newSelectors);

          // loop through our current selectors
          for (j = 0; j < newSelectors.length; j++) {
            sel = newSelectors[j];
            // if we don't have any parent paths, the & might be in a mixin so that it can be used
            // whether there are parents or not
            if (context.length === 0) {
              // the combinator used on el should now be applied to the next element instead so that
              // it is not lost
              if (sel.length > 0) {
                sel[0].elements.push(new Element(el.combinator, '', el.index, el.currentFileInfo));
              }
              selectorsMultiplied.push(sel);
            }
            else {
              // and the parent selectors
              for (k = 0; k < context.length; k++) {
                // We need to put the current selectors
                // then join the last selector's elements on to the parents selectors
                var newSelectorPath = addReplacementIntoPath(sel, context[k], el, inSelector);
                // add that to our new set of selectors
                selectorsMultiplied.push(newSelectorPath);
              }
            }
          }

          // our new selectors has been multiplied, so reset the state
          newSelectors = selectorsMultiplied;
          currentElements = [];
        }
      }

      // if we have any elements left over (e.g. .a& .b == .b)
      // add them on to all the current selectors
      mergeElementsOnToSelectors(currentElements, newSelectors);

      for (i = 0; i < newSelectors.length; i++) {
        length = newSelectors[i].length;
        if (length > 0) {
          paths.push(newSelectors[i]);
          lastSelector = newSelectors[i][length - 1];
          newSelectors[i][length - 1] = lastSelector.createDerived(lastSelector.elements, inSelector.extendList);
          //newSelectors[i][length - 1].copyVisibilityInfo(inSelector.visibilityInfo());
        }
      }

      return hadParentSelector;
    }

    function deriveSelector(visibilityInfo, deriveFrom) {
      var newSelector = deriveFrom.createDerived(deriveFrom.elements, deriveFrom.extendList, deriveFrom.evaldCondition);
      newSelector.copyVisibilityInfo(visibilityInfo);
      return newSelector;
    }

    // joinSelector code follows
    var i, newPaths, hadParentSelector;

    newPaths = [];
    hadParentSelector = replaceParentSelector(newPaths, context, selector);

    if (!hadParentSelector) {
      if (context.length > 0) {
        newPaths = [];
        for (i = 0; i < context.length; i++) {
          //var concatenated = [];
          //context[i].forEach(function(entry) {
          //    var newEntry = entry.createDerived(entry.elements, entry.extendList, entry.evaldCondition);
          //    newEntry.copyVisibilityInfo(selector.visibilityInfo());
          //    concatenated.push(newEntry);
          //}, this);
          var concatenated = context[i].map(deriveSelector.bind(this, selector.visibilityInfo()));

          concatenated.push(selector);
          newPaths.push(concatenated);
        }
      }
      else {
        newPaths = [[selector]];
      }
    }

    for (i = 0; i < newPaths.length; i++) {
      paths.push(newPaths[i]);
    }

  };
  module.exports = Ruleset;

},{"../contexts":11,"../functions/default":20,"../functions/function-registry":22,"./debug-info":54,"./element":58,"./node":70,"./paren":72,"./rule":74,"./selector":77}],77:[function(require,module,exports){
  var Node = require("./node"),
    Element = require("./element");

  var Selector = function (elements, extendList, condition, index, currentFileInfo, visibilityInfo) {
    this.elements = elements;
    this.extendList = extendList;
    this.condition = condition;
    this.currentFileInfo = currentFileInfo || {};
    if (!condition) {
      this.evaldCondition = true;
    }
    this.copyVisibilityInfo(visibilityInfo);
  };
  Selector.prototype = new Node();
  Selector.prototype.type = "Selector";
  Selector.prototype.accept = function (visitor) {
    if (this.elements) {
      this.elements = visitor.visitArray(this.elements);
    }
    if (this.extendList) {
      this.extendList = visitor.visitArray(this.extendList);
    }
    if (this.condition) {
      this.condition = visitor.visit(this.condition);
    }
  };
  Selector.prototype.createDerived = function(elements, extendList, evaldCondition) {
    var info = this.visibilityInfo();
    evaldCondition = (evaldCondition != null) ? evaldCondition : this.evaldCondition;
    var newSelector = new Selector(elements, extendList || this.extendList, null, this.index, this.currentFileInfo, info);
    newSelector.evaldCondition = evaldCondition;
    newSelector.mediaEmpty = this.mediaEmpty;
    return newSelector;
  };
  Selector.prototype.createEmptySelectors = function() {
    var el = new Element('', '&', this.index, this.currentFileInfo),
      sels = [new Selector([el], null, null, this.index, this.currentFileInfo)];
    sels[0].mediaEmpty = true;
    return sels;
  };
  Selector.prototype.match = function (other) {
    var elements = this.elements,
      len = elements.length,
      olen, i;

    other.CacheElements();

    olen = other._elements.length;
    if (olen === 0 || len < olen) {
      return 0;
    } else {
      for (i = 0; i < olen; i++) {
        if (elements[i].value !== other._elements[i]) {
          return 0;
        }
      }
    }

    return olen; // return number of matched elements
  };
  Selector.prototype.CacheElements = function() {
    if (this._elements) {
      return;
    }

    var elements = this.elements.map( function(v) {
      return v.combinator.value + (v.value.value || v.value);
    }).join("").match(/[,&#\*\.\w-]([\w-]|(\\.))*/g);

    if (elements) {
      if (elements[0] === "&") {
        elements.shift();
      }
    } else {
      elements = [];
    }

    this._elements = elements;
  };
  Selector.prototype.isJustParentSelector = function() {
    return !this.mediaEmpty &&
      this.elements.length === 1 &&
      this.elements[0].value === '&' &&
      (this.elements[0].combinator.value === ' ' || this.elements[0].combinator.value === '');
  };
  Selector.prototype.eval = function (context) {
    var evaldCondition = this.condition && this.condition.eval(context),
      elements = this.elements, extendList = this.extendList;

    elements = elements && elements.map(function (e) { return e.eval(context); });
    extendList = extendList && extendList.map(function(extend) { return extend.eval(context); });

    return this.createDerived(elements, extendList, evaldCondition);
  };
  Selector.prototype.genCSS = function (context, output) {
    var i, element;
    if ((!context || !context.firstSelector) && this.elements[0].combinator.value === "") {
      output.add(' ', this.currentFileInfo, this.index);
    }
    if (!this._css) {
      //TODO caching? speed comparison?
      for (i = 0; i < this.elements.length; i++) {
        element = this.elements[i];
        element.genCSS(context, output);
      }
    }
  };
  Selector.prototype.getIsOutput = function() {
    return this.evaldCondition;
  };
  module.exports = Selector;

},{"./element":58,"./node":70}],78:[function(require,module,exports){
  var Node = require("./node");

  var UnicodeDescriptor = function (value) {
    this.value = value;
  };
  UnicodeDescriptor.prototype = new Node();
  UnicodeDescriptor.prototype.type = "UnicodeDescriptor";

  module.exports = UnicodeDescriptor;

},{"./node":70}],79:[function(require,module,exports){
  var Node = require("./node"),
    unitConversions = require("../data/unit-conversions");

  var Unit = function (numerator, denominator, backupUnit) {
    this.numerator = numerator ? numerator.slice(0).sort() : [];
    this.denominator = denominator ? denominator.slice(0).sort() : [];
    if (backupUnit) {
      this.backupUnit = backupUnit;
    } else if (numerator && numerator.length) {
      this.backupUnit = numerator[0];
    }
  };

  Unit.prototype = new Node();
  Unit.prototype.type = "Unit";
  Unit.prototype.clone = function () {
    return new Unit(this.numerator.slice(0), this.denominator.slice(0), this.backupUnit);
  };
  Unit.prototype.genCSS = function (context, output) {
    // Dimension checks the unit is singular and throws an error if in strict math mode.
    var strictUnits = context && context.strictUnits;
    if (this.numerator.length === 1) {
      output.add(this.numerator[0]); // the ideal situation
    } else if (!strictUnits && this.backupUnit) {
      output.add(this.backupUnit);
    } else if (!strictUnits && this.denominator.length) {
      output.add(this.denominator[0]);
    }
  };
  Unit.prototype.toString = function () {
    var i, returnStr = this.numerator.join("*");
    for (i = 0; i < this.denominator.length; i++) {
      returnStr += "/" + this.denominator[i];
    }
    return returnStr;
  };
  Unit.prototype.compare = function (other) {
    return this.is(other.toString()) ? 0 : undefined;
  };
  Unit.prototype.is = function (unitString) {
    return this.toString().toUpperCase() === unitString.toUpperCase();
  };
  Unit.prototype.isLength = function () {
    return Boolean(this.toCSS().match(/px|em|%|in|cm|mm|pc|pt|ex/));
  };
  Unit.prototype.isEmpty = function () {
    return this.numerator.length === 0 && this.denominator.length === 0;
  };
  Unit.prototype.isSingular = function() {
    return this.numerator.length <= 1 && this.denominator.length === 0;
  };
  Unit.prototype.map = function(callback) {
    var i;

    for (i = 0; i < this.numerator.length; i++) {
      this.numerator[i] = callback(this.numerator[i], false);
    }

    for (i = 0; i < this.denominator.length; i++) {
      this.denominator[i] = callback(this.denominator[i], true);
    }
  };
  Unit.prototype.usedUnits = function() {
    var group, result = {}, mapUnit, groupName;

    mapUnit = function (atomicUnit) {
      /*jshint loopfunc:true */
      if (group.hasOwnProperty(atomicUnit) && !result[groupName]) {
        result[groupName] = atomicUnit;
      }

      return atomicUnit;
    };

    for (groupName in unitConversions) {
      if (unitConversions.hasOwnProperty(groupName)) {
        group = unitConversions[groupName];

        this.map(mapUnit);
      }
    }

    return result;
  };
  Unit.prototype.cancel = function () {
    var counter = {}, atomicUnit, i;

    for (i = 0; i < this.numerator.length; i++) {
      atomicUnit = this.numerator[i];
      counter[atomicUnit] = (counter[atomicUnit] || 0) + 1;
    }

    for (i = 0; i < this.denominator.length; i++) {
      atomicUnit = this.denominator[i];
      counter[atomicUnit] = (counter[atomicUnit] || 0) - 1;
    }

    this.numerator = [];
    this.denominator = [];

    for (atomicUnit in counter) {
      if (counter.hasOwnProperty(atomicUnit)) {
        var count = counter[atomicUnit];

        if (count > 0) {
          for (i = 0; i < count; i++) {
            this.numerator.push(atomicUnit);
          }
        } else if (count < 0) {
          for (i = 0; i < -count; i++) {
            this.denominator.push(atomicUnit);
          }
        }
      }
    }

    this.numerator.sort();
    this.denominator.sort();
  };
  module.exports = Unit;

},{"../data/unit-conversions":14,"./node":70}],80:[function(require,module,exports){
  var Node = require("./node");

  var URL = function (val, index, currentFileInfo, isEvald) {
    this.value = val;
    this.currentFileInfo = currentFileInfo;
    this.index = index;
    this.isEvald = isEvald;
  };
  URL.prototype = new Node();
  URL.prototype.type = "Url";
  URL.prototype.accept = function (visitor) {
    this.value = visitor.visit(this.value);
  };
  URL.prototype.genCSS = function (context, output) {
    output.add("url(");
    this.value.genCSS(context, output);
    output.add(")");
  };
  URL.prototype.eval = function (context) {
    var val = this.value.eval(context),
      rootpath;

    if (!this.isEvald) {
      // Add the base path if the URL is relative
      rootpath = this.currentFileInfo && this.currentFileInfo.rootpath;
      if (rootpath &&
        typeof val.value === "string" &&
        context.isPathRelative(val.value)) {

        if (!val.quote) {
          rootpath = rootpath.replace(/[\(\)'"\s]/g, function(match) { return "\\" + match; });
        }
        val.value = rootpath + val.value;
      }

      val.value = context.normalizePath(val.value);

      // Add url args if enabled
      if (context.urlArgs) {
        if (!val.value.match(/^\s*data:/)) {
          var delimiter = val.value.indexOf('?') === -1 ? '?' : '&';
          var urlArgs = delimiter + context.urlArgs;
          if (val.value.indexOf('#') !== -1) {
            val.value = val.value.replace('#', urlArgs + '#');
          } else {
            val.value += urlArgs;
          }
        }
      }
    }

    return new URL(val, this.index, this.currentFileInfo, true);
  };
  module.exports = URL;

},{"./node":70}],81:[function(require,module,exports){
  var Node = require("./node");

  var Value = function (value) {
    this.value = value;
    if (!value) {
      throw new Error("Value requires an array argument");
    }
  };
  Value.prototype = new Node();
  Value.prototype.type = "Value";
  Value.prototype.accept = function (visitor) {
    if (this.value) {
      this.value = visitor.visitArray(this.value);
    }
  };
  Value.prototype.eval = function (context) {
    if (this.value.length === 1) {
      return this.value[0].eval(context);
    } else {
      return new Value(this.value.map(function (v) {
        return v.eval(context);
      }));
    }
  };
  Value.prototype.genCSS = function (context, output) {
    var i;
    for (i = 0; i < this.value.length; i++) {
      this.value[i].genCSS(context, output);
      if (i + 1 < this.value.length) {
        output.add((context && context.compress) ? ',' : ', ');
      }
    }
  };
  module.exports = Value;

},{"./node":70}],82:[function(require,module,exports){
  var Node = require("./node");

  var Variable = function (name, index, currentFileInfo) {
    this.name = name;
    this.index = index;
    this.currentFileInfo = currentFileInfo || {};
  };
  Variable.prototype = new Node();
  Variable.prototype.type = "Variable";
  Variable.prototype.eval = function (context) {
    var variable, name = this.name;

    if (name.indexOf('@@') === 0) {
      name = '@' + new Variable(name.slice(1), this.index, this.currentFileInfo).eval(context).value;
    }

    if (this.evaluating) {
      throw { type: 'Name',
        message: "Recursive variable definition for " + name,
        filename: this.currentFileInfo.filename,
        index: this.index };
    }

    this.evaluating = true;

    variable = this.find(context.frames, function (frame) {
      var v = frame.variable(name);
      if (v) {
        if (v.important) {
          var importantScope = context.importantScope[context.importantScope.length - 1];
          importantScope.important = v.important;
        }
        return v.value.eval(context);
      }
    });
    if (variable) {
      this.evaluating = false;
      return variable;
    } else {
      throw { type: 'Name',
        message: "variable " + name + " is undefined",
        filename: this.currentFileInfo.filename,
        index: this.index };
    }
  };
  Variable.prototype.find = function (obj, fun) {
    for (var i = 0, r; i < obj.length; i++) {
      r = fun.call(obj, obj[i]);
      if (r) { return r; }
    }
    return null;
  };
  module.exports = Variable;

},{"./node":70}],83:[function(require,module,exports){
  module.exports = {
    getLocation: function(index, inputStream) {
      var n = index + 1,
        line = null,
        column = -1;

      while (--n >= 0 && inputStream.charAt(n) !== '\n') {
        column++;
      }

      if (typeof index === 'number') {
        line = (inputStream.slice(0, index).match(/\n/g) || "").length;
      }

      return {
        line: line,
        column: column
      };
    }
  };

},{}],84:[function(require,module,exports){
  var tree = require("../tree"),
    Visitor = require("./visitor"),
    logger = require("../logger");

  /*jshint loopfunc:true */

  var ExtendFinderVisitor = function() {
    this._visitor = new Visitor(this);
    this.contexts = [];
    this.allExtendsStack = [[]];
  };

  ExtendFinderVisitor.prototype = {
    run: function (root) {
      root = this._visitor.visit(root);
      root.allExtends = this.allExtendsStack[0];
      return root;
    },
    visitRule: function (ruleNode, visitArgs) {
      visitArgs.visitDeeper = false;
    },
    visitMixinDefinition: function (mixinDefinitionNode, visitArgs) {
      visitArgs.visitDeeper = false;
    },
    visitRuleset: function (rulesetNode, visitArgs) {
      if (rulesetNode.root) {
        return;
      }

      var i, j, extend, allSelectorsExtendList = [], extendList;

      // get &:extend(.a); rules which apply to all selectors in this ruleset
      var rules = rulesetNode.rules, ruleCnt = rules ? rules.length : 0;
      for (i = 0; i < ruleCnt; i++) {
        if (rulesetNode.rules[i] instanceof tree.Extend) {
          allSelectorsExtendList.push(rules[i]);
          rulesetNode.extendOnEveryPath = true;
        }
      }

      // now find every selector and apply the extends that apply to all extends
      // and the ones which apply to an individual extend
      var paths = rulesetNode.paths;
      for (i = 0; i < paths.length; i++) {
        var selectorPath = paths[i],
          selector = selectorPath[selectorPath.length - 1],
          selExtendList = selector.extendList;

        extendList = selExtendList ? selExtendList.slice(0).concat(allSelectorsExtendList)
          : allSelectorsExtendList;

        if (extendList) {
          extendList = extendList.map(function(allSelectorsExtend) {
            return allSelectorsExtend.clone();
          });
        }

        for (j = 0; j < extendList.length; j++) {
          this.foundExtends = true;
          extend = extendList[j];
          extend.findSelfSelectors(selectorPath);
          extend.ruleset = rulesetNode;
          if (j === 0) { extend.firstExtendOnThisSelectorPath = true; }
          this.allExtendsStack[this.allExtendsStack.length - 1].push(extend);
        }
      }

      this.contexts.push(rulesetNode.selectors);
    },
    visitRulesetOut: function (rulesetNode) {
      if (!rulesetNode.root) {
        this.contexts.length = this.contexts.length - 1;
      }
    },
    visitMedia: function (mediaNode, visitArgs) {
      mediaNode.allExtends = [];
      this.allExtendsStack.push(mediaNode.allExtends);
    },
    visitMediaOut: function (mediaNode) {
      this.allExtendsStack.length = this.allExtendsStack.length - 1;
    },
    visitDirective: function (directiveNode, visitArgs) {
      directiveNode.allExtends = [];
      this.allExtendsStack.push(directiveNode.allExtends);
    },
    visitDirectiveOut: function (directiveNode) {
      this.allExtendsStack.length = this.allExtendsStack.length - 1;
    }
  };

  var ProcessExtendsVisitor = function() {
    this._visitor = new Visitor(this);
  };

  ProcessExtendsVisitor.prototype = {
    run: function(root) {
      var extendFinder = new ExtendFinderVisitor();
      this.extendIndices = {};
      extendFinder.run(root);
      if (!extendFinder.foundExtends) { return root; }
      root.allExtends = root.allExtends.concat(this.doExtendChaining(root.allExtends, root.allExtends));
      this.allExtendsStack = [root.allExtends];
      var newRoot = this._visitor.visit(root);
      this.checkExtendsForNonMatched(root.allExtends);
      return newRoot;
    },
    checkExtendsForNonMatched: function(extendList) {
      var indices = this.extendIndices;
      extendList.filter(function(extend) {
        return !extend.hasFoundMatches && extend.parent_ids.length == 1;
      }).forEach(function(extend) {
        var selector = "_unknown_";
        try {
          selector = extend.selector.toCSS({});
        }
        catch(_) {}

        if (!indices[extend.index + ' ' + selector]) {
          indices[extend.index + ' ' + selector] = true;
          logger.warn("extend '" + selector + "' has no matches");
        }
      });
    },
    doExtendChaining: function (extendsList, extendsListTarget, iterationCount) {
      //
      // chaining is different from normal extension.. if we extend an extend then we are not just copying, altering
      // and pasting the selector we would do normally, but we are also adding an extend with the same target selector
      // this means this new extend can then go and alter other extends
      //
      // this method deals with all the chaining work - without it, extend is flat and doesn't work on other extend selectors
      // this is also the most expensive.. and a match on one selector can cause an extension of a selector we had already
      // processed if we look at each selector at a time, as is done in visitRuleset

      var extendIndex, targetExtendIndex, matches, extendsToAdd = [], newSelector, extendVisitor = this, selectorPath,
        extend, targetExtend, newExtend;

      iterationCount = iterationCount || 0;

      //loop through comparing every extend with every target extend.
      // a target extend is the one on the ruleset we are looking at copy/edit/pasting in place
      // e.g.  .a:extend(.b) {}  and .b:extend(.c) {} then the first extend extends the second one
      // and the second is the target.
      // the separation into two lists allows us to process a subset of chains with a bigger set, as is the
      // case when processing media queries
      for (extendIndex = 0; extendIndex < extendsList.length; extendIndex++) {
        for (targetExtendIndex = 0; targetExtendIndex < extendsListTarget.length; targetExtendIndex++) {

          extend = extendsList[extendIndex];
          targetExtend = extendsListTarget[targetExtendIndex];

          // look for circular references
          if ( extend.parent_ids.indexOf( targetExtend.object_id ) >= 0 ) { continue; }

          // find a match in the target extends self selector (the bit before :extend)
          selectorPath = [targetExtend.selfSelectors[0]];
          matches = extendVisitor.findMatch(extend, selectorPath);

          if (matches.length) {
            extend.hasFoundMatches = true;

            // we found a match, so for each self selector..
            extend.selfSelectors.forEach(function(selfSelector) {
              var info = targetExtend.visibilityInfo();

              // process the extend as usual
              newSelector = extendVisitor.extendSelector(matches, selectorPath, selfSelector, extend.isVisible());

              // but now we create a new extend from it
              newExtend = new(tree.Extend)(targetExtend.selector, targetExtend.option, 0, targetExtend.currentFileInfo, info);
              newExtend.selfSelectors = newSelector;

              // add the extend onto the list of extends for that selector
              newSelector[newSelector.length - 1].extendList = [newExtend];

              // record that we need to add it.
              extendsToAdd.push(newExtend);
              newExtend.ruleset = targetExtend.ruleset;

              //remember its parents for circular references
              newExtend.parent_ids = newExtend.parent_ids.concat(targetExtend.parent_ids, extend.parent_ids);

              // only process the selector once.. if we have :extend(.a,.b) then multiple
              // extends will look at the same selector path, so when extending
              // we know that any others will be duplicates in terms of what is added to the css
              if (targetExtend.firstExtendOnThisSelectorPath) {
                newExtend.firstExtendOnThisSelectorPath = true;
                targetExtend.ruleset.paths.push(newSelector);
              }
            });
          }
        }
      }

      if (extendsToAdd.length) {
        // try to detect circular references to stop a stack overflow.
        // may no longer be needed.
        this.extendChainCount++;
        if (iterationCount > 100) {
          var selectorOne = "{unable to calculate}";
          var selectorTwo = "{unable to calculate}";
          try {
            selectorOne = extendsToAdd[0].selfSelectors[0].toCSS();
            selectorTwo = extendsToAdd[0].selector.toCSS();
          }
          catch(e) {}
          throw { message: "extend circular reference detected. One of the circular extends is currently:" +
          selectorOne + ":extend(" + selectorTwo + ")"};
        }

        // now process the new extends on the existing rules so that we can handle a extending b extending c extending
        // d extending e...
        return extendsToAdd.concat(extendVisitor.doExtendChaining(extendsToAdd, extendsListTarget, iterationCount + 1));
      } else {
        return extendsToAdd;
      }
    },
    visitRule: function (ruleNode, visitArgs) {
      visitArgs.visitDeeper = false;
    },
    visitMixinDefinition: function (mixinDefinitionNode, visitArgs) {
      visitArgs.visitDeeper = false;
    },
    visitSelector: function (selectorNode, visitArgs) {
      visitArgs.visitDeeper = false;
    },
    visitRuleset: function (rulesetNode, visitArgs) {
      if (rulesetNode.root) {
        return;
      }
      var matches, pathIndex, extendIndex, allExtends = this.allExtendsStack[this.allExtendsStack.length - 1],
        selectorsToAdd = [], extendVisitor = this, selectorPath;

      // look at each selector path in the ruleset, find any extend matches and then copy, find and replace

      for (extendIndex = 0; extendIndex < allExtends.length; extendIndex++) {
        for (pathIndex = 0; pathIndex < rulesetNode.paths.length; pathIndex++) {
          selectorPath = rulesetNode.paths[pathIndex];

          // extending extends happens initially, before the main pass
          if (rulesetNode.extendOnEveryPath) { continue; }
          var extendList = selectorPath[selectorPath.length - 1].extendList;
          if (extendList && extendList.length) { continue; }

          matches = this.findMatch(allExtends[extendIndex], selectorPath);

          if (matches.length) {
            allExtends[extendIndex].hasFoundMatches = true;

            allExtends[extendIndex].selfSelectors.forEach(function(selfSelector) {
              var extendedSelectors;
              extendedSelectors = extendVisitor.extendSelector(matches, selectorPath, selfSelector, allExtends[extendIndex].isVisible());
              selectorsToAdd.push(extendedSelectors);
            });
          }
        }
      }
      rulesetNode.paths = rulesetNode.paths.concat(selectorsToAdd);
    },
    findMatch: function (extend, haystackSelectorPath) {
      //
      // look through the haystack selector path to try and find the needle - extend.selector
      // returns an array of selector matches that can then be replaced
      //
      var haystackSelectorIndex, hackstackSelector, hackstackElementIndex, haystackElement,
        targetCombinator, i,
        extendVisitor = this,
        needleElements = extend.selector.elements,
        potentialMatches = [], potentialMatch, matches = [];

      // loop through the haystack elements
      for (haystackSelectorIndex = 0; haystackSelectorIndex < haystackSelectorPath.length; haystackSelectorIndex++) {
        hackstackSelector = haystackSelectorPath[haystackSelectorIndex];

        for (hackstackElementIndex = 0; hackstackElementIndex < hackstackSelector.elements.length; hackstackElementIndex++) {

          haystackElement = hackstackSelector.elements[hackstackElementIndex];

          // if we allow elements before our match we can add a potential match every time. otherwise only at the first element.
          if (extend.allowBefore || (haystackSelectorIndex === 0 && hackstackElementIndex === 0)) {
            potentialMatches.push({pathIndex: haystackSelectorIndex, index: hackstackElementIndex, matched: 0,
              initialCombinator: haystackElement.combinator});
          }

          for (i = 0; i < potentialMatches.length; i++) {
            potentialMatch = potentialMatches[i];

            // selectors add " " onto the first element. When we use & it joins the selectors together, but if we don't
            // then each selector in haystackSelectorPath has a space before it added in the toCSS phase. so we need to
            // work out what the resulting combinator will be
            targetCombinator = haystackElement.combinator.value;
            if (targetCombinator === '' && hackstackElementIndex === 0) {
              targetCombinator = ' ';
            }

            // if we don't match, null our match to indicate failure
            if (!extendVisitor.isElementValuesEqual(needleElements[potentialMatch.matched].value, haystackElement.value) ||
              (potentialMatch.matched > 0 && needleElements[potentialMatch.matched].combinator.value !== targetCombinator)) {
              potentialMatch = null;
            } else {
              potentialMatch.matched++;
            }

            // if we are still valid and have finished, test whether we have elements after and whether these are allowed
            if (potentialMatch) {
              potentialMatch.finished = potentialMatch.matched === needleElements.length;
              if (potentialMatch.finished &&
                (!extend.allowAfter &&
                  (hackstackElementIndex + 1 < hackstackSelector.elements.length || haystackSelectorIndex + 1 < haystackSelectorPath.length))) {
                potentialMatch = null;
              }
            }
            // if null we remove, if not, we are still valid, so either push as a valid match or continue
            if (potentialMatch) {
              if (potentialMatch.finished) {
                potentialMatch.length = needleElements.length;
                potentialMatch.endPathIndex = haystackSelectorIndex;
                potentialMatch.endPathElementIndex = hackstackElementIndex + 1; // index after end of match
                potentialMatches.length = 0; // we don't allow matches to overlap, so start matching again
                matches.push(potentialMatch);
              }
            } else {
              potentialMatches.splice(i, 1);
              i--;
            }
          }
        }
      }
      return matches;
    },
    isElementValuesEqual: function(elementValue1, elementValue2) {
      if (typeof elementValue1 === "string" || typeof elementValue2 === "string") {
        return elementValue1 === elementValue2;
      }
      if (elementValue1 instanceof tree.Attribute) {
        if (elementValue1.op !== elementValue2.op || elementValue1.key !== elementValue2.key) {
          return false;
        }
        if (!elementValue1.value || !elementValue2.value) {
          if (elementValue1.value || elementValue2.value) {
            return false;
          }
          return true;
        }
        elementValue1 = elementValue1.value.value || elementValue1.value;
        elementValue2 = elementValue2.value.value || elementValue2.value;
        return elementValue1 === elementValue2;
      }
      elementValue1 = elementValue1.value;
      elementValue2 = elementValue2.value;
      if (elementValue1 instanceof tree.Selector) {
        if (!(elementValue2 instanceof tree.Selector) || elementValue1.elements.length !== elementValue2.elements.length) {
          return false;
        }
        for (var i = 0; i  < elementValue1.elements.length; i++) {
          if (elementValue1.elements[i].combinator.value !== elementValue2.elements[i].combinator.value) {
            if (i !== 0 || (elementValue1.elements[i].combinator.value || ' ') !== (elementValue2.elements[i].combinator.value || ' ')) {
              return false;
            }
          }
          if (!this.isElementValuesEqual(elementValue1.elements[i].value, elementValue2.elements[i].value)) {
            return false;
          }
        }
        return true;
      }
      return false;
    },
    extendSelector:function (matches, selectorPath, replacementSelector, isVisible) {

      //for a set of matches, replace each match with the replacement selector

      var currentSelectorPathIndex = 0,
        currentSelectorPathElementIndex = 0,
        path = [],
        matchIndex,
        selector,
        firstElement,
        match,
        newElements;

      for (matchIndex = 0; matchIndex < matches.length; matchIndex++) {
        match = matches[matchIndex];
        selector = selectorPath[match.pathIndex];
        firstElement = new tree.Element(
          match.initialCombinator,
          replacementSelector.elements[0].value,
          replacementSelector.elements[0].index,
          replacementSelector.elements[0].currentFileInfo
        );

        if (match.pathIndex > currentSelectorPathIndex && currentSelectorPathElementIndex > 0) {
          path[path.length - 1].elements = path[path.length - 1]
            .elements.concat(selectorPath[currentSelectorPathIndex].elements.slice(currentSelectorPathElementIndex));
          currentSelectorPathElementIndex = 0;
          currentSelectorPathIndex++;
        }

        newElements = selector.elements
          .slice(currentSelectorPathElementIndex, match.index)
          .concat([firstElement])
          .concat(replacementSelector.elements.slice(1));

        if (currentSelectorPathIndex === match.pathIndex && matchIndex > 0) {
          path[path.length - 1].elements =
            path[path.length - 1].elements.concat(newElements);
        } else {
          path = path.concat(selectorPath.slice(currentSelectorPathIndex, match.pathIndex));

          path.push(new tree.Selector(
            newElements
          ));
        }
        currentSelectorPathIndex = match.endPathIndex;
        currentSelectorPathElementIndex = match.endPathElementIndex;
        if (currentSelectorPathElementIndex >= selectorPath[currentSelectorPathIndex].elements.length) {
          currentSelectorPathElementIndex = 0;
          currentSelectorPathIndex++;
        }
      }

      if (currentSelectorPathIndex < selectorPath.length && currentSelectorPathElementIndex > 0) {
        path[path.length - 1].elements = path[path.length - 1]
          .elements.concat(selectorPath[currentSelectorPathIndex].elements.slice(currentSelectorPathElementIndex));
        currentSelectorPathIndex++;
      }

      path = path.concat(selectorPath.slice(currentSelectorPathIndex, selectorPath.length));
      path = path.map(function (currentValue) {
        // we can re-use elements here, because the visibility property matters only for selectors
        var derived = currentValue.createDerived(currentValue.elements);
        if (isVisible) {
          derived.ensureVisibility();
        } else {
          derived.ensureInvisibility();
        }
        return derived;
      });
      return path;
    },
    visitMedia: function (mediaNode, visitArgs) {
      var newAllExtends = mediaNode.allExtends.concat(this.allExtendsStack[this.allExtendsStack.length - 1]);
      newAllExtends = newAllExtends.concat(this.doExtendChaining(newAllExtends, mediaNode.allExtends));
      this.allExtendsStack.push(newAllExtends);
    },
    visitMediaOut: function (mediaNode) {
      var lastIndex = this.allExtendsStack.length - 1;
      this.allExtendsStack.length = lastIndex;
    },
    visitDirective: function (directiveNode, visitArgs) {
      var newAllExtends = directiveNode.allExtends.concat(this.allExtendsStack[this.allExtendsStack.length - 1]);
      newAllExtends = newAllExtends.concat(this.doExtendChaining(newAllExtends, directiveNode.allExtends));
      this.allExtendsStack.push(newAllExtends);
    },
    visitDirectiveOut: function (directiveNode) {
      var lastIndex = this.allExtendsStack.length - 1;
      this.allExtendsStack.length = lastIndex;
    }
  };

  module.exports = ProcessExtendsVisitor;

},{"../logger":33,"../tree":62,"./visitor":91}],85:[function(require,module,exports){
  function ImportSequencer(onSequencerEmpty) {
    this.imports = [];
    this.variableImports = [];
    this._onSequencerEmpty = onSequencerEmpty;
    this._currentDepth = 0;
  }

  ImportSequencer.prototype.addImport = function(callback) {
    var importSequencer = this,
      importItem = {
        callback: callback,
        args: null,
        isReady: false
      };
    this.imports.push(importItem);
    return function() {
      importItem.args = Array.prototype.slice.call(arguments, 0);
      importItem.isReady = true;
      importSequencer.tryRun();
    };
  };

  ImportSequencer.prototype.addVariableImport = function(callback) {
    this.variableImports.push(callback);
  };

  ImportSequencer.prototype.tryRun = function() {
    this._currentDepth++;
    try {
      while (true) {
        while (this.imports.length > 0) {
          var importItem = this.imports[0];
          if (!importItem.isReady) {
            return;
          }
          this.imports = this.imports.slice(1);
          importItem.callback.apply(null, importItem.args);
        }
        if (this.variableImports.length === 0) {
          break;
        }
        var variableImport = this.variableImports[0];
        this.variableImports = this.variableImports.slice(1);
        variableImport();
      }
    } finally {
      this._currentDepth--;
    }
    if (this._currentDepth === 0 && this._onSequencerEmpty) {
      this._onSequencerEmpty();
    }
  };

  module.exports = ImportSequencer;

},{}],86:[function(require,module,exports){
  var contexts = require("../contexts"),
    Visitor = require("./visitor"),
    ImportSequencer = require("./import-sequencer");

  var ImportVisitor = function(importer, finish) {

    this._visitor = new Visitor(this);
    this._importer = importer;
    this._finish = finish;
    this.context = new contexts.Eval();
    this.importCount = 0;
    this.onceFileDetectionMap = {};
    this.recursionDetector = {};
    this._sequencer = new ImportSequencer(this._onSequencerEmpty.bind(this));
  };

  ImportVisitor.prototype = {
    isReplacing: false,
    run: function (root) {
      try {
        // process the contents
        this._visitor.visit(root);
      }
      catch(e) {
        this.error = e;
      }

      this.isFinished = true;
      this._sequencer.tryRun();
    },
    _onSequencerEmpty: function() {
      if (!this.isFinished) {
        return;
      }
      this._finish(this.error);
    },
    visitImport: function (importNode, visitArgs) {
      var inlineCSS = importNode.options.inline;

      if (!importNode.css || inlineCSS) {

        var context = new contexts.Eval(this.context, this.context.frames.slice(0));
        var importParent = context.frames[0];

        this.importCount++;
        if (importNode.isVariableImport()) {
          this._sequencer.addVariableImport(this.processImportNode.bind(this, importNode, context, importParent));
        } else {
          this.processImportNode(importNode, context, importParent);
        }
      }
      visitArgs.visitDeeper = false;
    },
    processImportNode: function(importNode, context, importParent) {
      var evaldImportNode,
        inlineCSS = importNode.options.inline;

      try {
        evaldImportNode = importNode.evalForImport(context);
      } catch(e) {
        if (!e.filename) { e.index = importNode.index; e.filename = importNode.currentFileInfo.filename; }
        // attempt to eval properly and treat as css
        importNode.css = true;
        // if that fails, this error will be thrown
        importNode.error = e;
      }

      if (evaldImportNode && (!evaldImportNode.css || inlineCSS)) {

        if (evaldImportNode.options.multiple) {
          context.importMultiple = true;
        }

        // try appending if we haven't determined if it is css or not
        var tryAppendLessExtension = evaldImportNode.css === undefined;

        for (var i = 0; i < importParent.rules.length; i++) {
          if (importParent.rules[i] === importNode) {
            importParent.rules[i] = evaldImportNode;
            break;
          }
        }

        var onImported = this.onImported.bind(this, evaldImportNode, context),
          sequencedOnImported = this._sequencer.addImport(onImported);

        this._importer.push(evaldImportNode.getPath(), tryAppendLessExtension, evaldImportNode.currentFileInfo,
          evaldImportNode.options, sequencedOnImported);
      } else {
        this.importCount--;
        if (this.isFinished) {
          this._sequencer.tryRun();
        }
      }
    },
    onImported: function (importNode, context, e, root, importedAtRoot, fullPath) {
      if (e) {
        if (!e.filename) {
          e.index = importNode.index; e.filename = importNode.currentFileInfo.filename;
        }
        this.error = e;
      }

      var importVisitor = this,
        inlineCSS = importNode.options.inline,
        isPlugin = importNode.options.plugin,
        isOptional = importNode.options.optional,
        duplicateImport = importedAtRoot || fullPath in importVisitor.recursionDetector;

      if (!context.importMultiple) {
        if (duplicateImport) {
          importNode.skip = true;
        } else {
          importNode.skip = function() {
            if (fullPath in importVisitor.onceFileDetectionMap) {
              return true;
            }
            importVisitor.onceFileDetectionMap[fullPath] = true;
            return false;
          };
        }
      }

      if (!fullPath && isOptional) {
        importNode.skip = true;
      }

      if (root) {
        importNode.root = root;
        importNode.importedFilename = fullPath;

        if (!inlineCSS && !isPlugin && (context.importMultiple || !duplicateImport)) {
          importVisitor.recursionDetector[fullPath] = true;

          var oldContext = this.context;
          this.context = context;
          try {
            this._visitor.visit(root);
          } catch (e) {
            this.error = e;
          }
          this.context = oldContext;
        }
      }

      importVisitor.importCount--;

      if (importVisitor.isFinished) {
        importVisitor._sequencer.tryRun();
      }
    },
    visitRule: function (ruleNode, visitArgs) {
      if (ruleNode.value.type === "DetachedRuleset") {
        this.context.frames.unshift(ruleNode);
      } else {
        visitArgs.visitDeeper = false;
      }
    },
    visitRuleOut : function(ruleNode) {
      if (ruleNode.value.type === "DetachedRuleset") {
        this.context.frames.shift();
      }
    },
    visitDirective: function (directiveNode, visitArgs) {
      this.context.frames.unshift(directiveNode);
    },
    visitDirectiveOut: function (directiveNode) {
      this.context.frames.shift();
    },
    visitMixinDefinition: function (mixinDefinitionNode, visitArgs) {
      this.context.frames.unshift(mixinDefinitionNode);
    },
    visitMixinDefinitionOut: function (mixinDefinitionNode) {
      this.context.frames.shift();
    },
    visitRuleset: function (rulesetNode, visitArgs) {
      this.context.frames.unshift(rulesetNode);
    },
    visitRulesetOut: function (rulesetNode) {
      this.context.frames.shift();
    },
    visitMedia: function (mediaNode, visitArgs) {
      this.context.frames.unshift(mediaNode.rules[0]);
    },
    visitMediaOut: function (mediaNode) {
      this.context.frames.shift();
    }
  };
  module.exports = ImportVisitor;

},{"../contexts":11,"./import-sequencer":85,"./visitor":91}],87:[function(require,module,exports){
  var visitors = {
    Visitor: require("./visitor"),
    ImportVisitor: require('./import-visitor'),
    MarkVisibleSelectorsVisitor: require("./set-tree-visibility-visitor"),
    ExtendVisitor: require('./extend-visitor'),
    JoinSelectorVisitor: require('./join-selector-visitor'),
    ToCSSVisitor: require('./to-css-visitor')
  };

  module.exports = visitors;

},{"./extend-visitor":84,"./import-visitor":86,"./join-selector-visitor":88,"./set-tree-visibility-visitor":89,"./to-css-visitor":90,"./visitor":91}],88:[function(require,module,exports){
  var Visitor = require("./visitor");

  var JoinSelectorVisitor = function() {
    this.contexts = [[]];
    this._visitor = new Visitor(this);
  };

  JoinSelectorVisitor.prototype = {
    run: function (root) {
      return this._visitor.visit(root);
    },
    visitRule: function (ruleNode, visitArgs) {
      visitArgs.visitDeeper = false;
    },
    visitMixinDefinition: function (mixinDefinitionNode, visitArgs) {
      visitArgs.visitDeeper = false;
    },

    visitRuleset: function (rulesetNode, visitArgs) {
      var context = this.contexts[this.contexts.length - 1],
        paths = [], selectors;

      this.contexts.push(paths);

      if (! rulesetNode.root) {
        selectors = rulesetNode.selectors;
        if (selectors) {
          selectors = selectors.filter(function(selector) { return selector.getIsOutput(); });
          rulesetNode.selectors = selectors.length ? selectors : (selectors = null);
          if (selectors) { rulesetNode.joinSelectors(paths, context, selectors); }
        }
        if (!selectors) { rulesetNode.rules = null; }
        rulesetNode.paths = paths;
      }
    },
    visitRulesetOut: function (rulesetNode) {
      this.contexts.length = this.contexts.length - 1;
    },
    visitMedia: function (mediaNode, visitArgs) {
      var context = this.contexts[this.contexts.length - 1];
      mediaNode.rules[0].root = (context.length === 0 || context[0].multiMedia);
    },
    visitDirective: function (directiveNode, visitArgs) {
      var context = this.contexts[this.contexts.length - 1];
      if (directiveNode.rules && directiveNode.rules.length) {
        directiveNode.rules[0].root = (directiveNode.isRooted || context.length === 0 || null);
      }
    }
  };

  module.exports = JoinSelectorVisitor;

},{"./visitor":91}],89:[function(require,module,exports){
  var SetTreeVisibilityVisitor = function(visible) {
    this.visible = visible;
  };
  SetTreeVisibilityVisitor.prototype.run = function(root) {
    this.visit(root);
  };
  SetTreeVisibilityVisitor.prototype.visitArray = function(nodes) {
    if (!nodes) {
      return nodes;
    }

    var cnt = nodes.length, i;
    for (i = 0; i < cnt; i++) {
      this.visit(nodes[i]);
    }
    return nodes;
  };
  SetTreeVisibilityVisitor.prototype.visit = function(node) {
    if (!node) {
      return node;
    }
    if (node.constructor === Array) {
      return this.visitArray(node);
    }

    if (!node.blocksVisibility || node.blocksVisibility()) {
      return node;
    }
    if (this.visible) {
      node.ensureVisibility();
    } else {
      node.ensureInvisibility();
    }

    node.accept(this);
    return node;
  };
  module.exports = SetTreeVisibilityVisitor;
},{}],90:[function(require,module,exports){
  var tree = require("../tree"),
    Visitor = require("./visitor");

  var CSSVisitorUtils = function(context) {
    this._visitor = new Visitor(this);
    this._context = context;
  };

  CSSVisitorUtils.prototype = {
    containsSilentNonBlockedChild: function(bodyRules) {
      var rule;
      if (bodyRules == null) {
        return false;
      }
      for (var r = 0; r < bodyRules.length; r++) {
        rule = bodyRules[r];
        if (rule.isSilent && rule.isSilent(this._context) && !rule.blocksVisibility()) {
          //the directive contains something that was referenced (likely by extend)
          //therefore it needs to be shown in output too
          return true;
        }
      }
      return false;
    },

    keepOnlyVisibleChilds: function(owner) {
      if (owner == null || owner.rules == null) {
        return ;
      }

      owner.rules = owner.rules.filter(function(thing) {
          return thing.isVisible();
        }
      );
    },

    isEmpty: function(owner) {
      if (owner == null || owner.rules == null) {
        return true;
      }
      return owner.rules.length === 0;
    },

    hasVisibleSelector: function(rulesetNode) {
      if (rulesetNode == null || rulesetNode.paths == null) {
        return false;
      }
      return rulesetNode.paths.length > 0;
    },

    resolveVisibility: function (node, originalRules) {
      if (!node.blocksVisibility()) {
        if (this.isEmpty(node) && !this.containsSilentNonBlockedChild(originalRules)) {
          return ;
        }

        return node;
      }

      var compiledRulesBody = node.rules[0];
      this.keepOnlyVisibleChilds(compiledRulesBody);

      if (this.isEmpty(compiledRulesBody)) {
        return ;
      }

      node.ensureVisibility();
      node.removeVisibilityBlock();

      return node;
    },

    isVisibleRuleset: function(rulesetNode) {
      if (rulesetNode.firstRoot) {
        return true;
      }

      if (this.isEmpty(rulesetNode)) {
        return false;
      }

      if (!rulesetNode.root && !this.hasVisibleSelector(rulesetNode)) {
        return false;
      }

      return true;
    }

  };

  var ToCSSVisitor = function(context) {
    this._visitor = new Visitor(this);
    this._context = context;
    this.utils = new CSSVisitorUtils(context);
  };

  ToCSSVisitor.prototype = {
    isReplacing: true,
    run: function (root) {
      return this._visitor.visit(root);
    },

    visitRule: function (ruleNode, visitArgs) {
      if (ruleNode.blocksVisibility() || ruleNode.variable) {
        return;
      }
      return ruleNode;
    },

    visitMixinDefinition: function (mixinNode, visitArgs) {
      // mixin definitions do not get eval'd - this means they keep state
      // so we have to clear that state here so it isn't used if toCSS is called twice
      mixinNode.frames = [];
    },

    visitExtend: function (extendNode, visitArgs) {
    },

    visitComment: function (commentNode, visitArgs) {
      if (commentNode.blocksVisibility() || commentNode.isSilent(this._context)) {
        return;
      }
      return commentNode;
    },

    visitMedia: function(mediaNode, visitArgs) {
      var originalRules = mediaNode.rules[0].rules;
      mediaNode.accept(this._visitor);
      visitArgs.visitDeeper = false;

      return this.utils.resolveVisibility(mediaNode, originalRules);
    },

    visitImport: function (importNode, visitArgs) {
      if (importNode.blocksVisibility()) {
        return ;
      }
      return importNode;
    },

    visitDirective: function(directiveNode, visitArgs) {
      if (directiveNode.rules && directiveNode.rules.length) {
        return this.visitDirectiveWithBody(directiveNode, visitArgs);
      } else {
        return this.visitDirectiveWithoutBody(directiveNode, visitArgs);
      }
    },

    visitDirectiveWithBody: function(directiveNode, visitArgs) {
      //if there is only one nested ruleset and that one has no path, then it is
      //just fake ruleset
      function hasFakeRuleset(directiveNode) {
        var bodyRules = directiveNode.rules;
        return bodyRules.length === 1 && (!bodyRules[0].paths || bodyRules[0].paths.length === 0);
      }
      function getBodyRules(directiveNode) {
        var nodeRules = directiveNode.rules;
        if (hasFakeRuleset(directiveNode)) {
          return nodeRules[0].rules;
        }

        return nodeRules;
      }
      //it is still true that it is only one ruleset in array
      //this is last such moment
      //process childs
      var originalRules = getBodyRules(directiveNode);
      directiveNode.accept(this._visitor);
      visitArgs.visitDeeper = false;

      if (!this.utils.isEmpty(directiveNode)) {
        this._mergeRules(directiveNode.rules[0].rules);
      }

      return this.utils.resolveVisibility(directiveNode, originalRules);
    },

    visitDirectiveWithoutBody: function(directiveNode, visitArgs) {
      if (directiveNode.blocksVisibility()) {
        return;
      }

      if (directiveNode.name === "@charset") {
        // Only output the debug info together with subsequent @charset definitions
        // a comment (or @media statement) before the actual @charset directive would
        // be considered illegal css as it has to be on the first line
        if (this.charset) {
          if (directiveNode.debugInfo) {
            var comment = new tree.Comment("/* " + directiveNode.toCSS(this._context).replace(/\n/g, "") + " */\n");
            comment.debugInfo = directiveNode.debugInfo;
            return this._visitor.visit(comment);
          }
          return;
        }
        this.charset = true;
      }

      return directiveNode;
    },

    checkValidNodes: function(rules, isRoot) {
      if (!rules) {
        return;
      }

      for (var i = 0; i < rules.length; i++) {
        var ruleNode = rules[i];
        if (isRoot && ruleNode instanceof tree.Rule && !ruleNode.variable) {
          throw { message: "Properties must be inside selector blocks. They cannot be in the root",
            index: ruleNode.index, filename: ruleNode.currentFileInfo && ruleNode.currentFileInfo.filename};
        }
        if (ruleNode instanceof tree.Call) {
          throw { message: "Function '" + ruleNode.name + "' is undefined",
            index: ruleNode.index, filename: ruleNode.currentFileInfo && ruleNode.currentFileInfo.filename};
        }
        if (ruleNode.type && !ruleNode.allowRoot) {
          throw { message: ruleNode.type + " node returned by a function is not valid here",
            index: ruleNode.index, filename: ruleNode.currentFileInfo && ruleNode.currentFileInfo.filename};
        }
      }
    },

    visitRuleset: function (rulesetNode, visitArgs) {
      //at this point rulesets are nested into each other
      var rule, rulesets = [];

      this.checkValidNodes(rulesetNode.rules, rulesetNode.firstRoot);

      if (! rulesetNode.root) {
        //remove invisible paths
        this._compileRulesetPaths(rulesetNode);

        // remove rulesets from this ruleset body and compile them separately
        var nodeRules = rulesetNode.rules, nodeRuleCnt = nodeRules ? nodeRules.length : 0;
        for (var i = 0; i < nodeRuleCnt; ) {
          rule = nodeRules[i];
          if (rule && rule.rules) {
            // visit because we are moving them out from being a child
            rulesets.push(this._visitor.visit(rule));
            nodeRules.splice(i, 1);
            nodeRuleCnt--;
            continue;
          }
          i++;
        }
        // accept the visitor to remove rules and refactor itself
        // then we can decide nogw whether we want it or not
        // compile body
        if (nodeRuleCnt > 0) {
          rulesetNode.accept(this._visitor);
        } else {
          rulesetNode.rules = null;
        }
        visitArgs.visitDeeper = false;

      } else { //if (! rulesetNode.root) {
        rulesetNode.accept(this._visitor);
        visitArgs.visitDeeper = false;
      }

      if (rulesetNode.rules) {
        this._mergeRules(rulesetNode.rules);
        this._removeDuplicateRules(rulesetNode.rules);
      }

      //now decide whether we keep the ruleset
      if (this.utils.isVisibleRuleset(rulesetNode)) {
        rulesetNode.ensureVisibility();
        rulesets.splice(0, 0, rulesetNode);
      }

      if (rulesets.length === 1) {
        return rulesets[0];
      }
      return rulesets;
    },

    _compileRulesetPaths: function(rulesetNode) {
      if (rulesetNode.paths) {
        rulesetNode.paths = rulesetNode.paths
          .filter(function(p) {
            var i;
            if (p[0].elements[0].combinator.value === ' ') {
              p[0].elements[0].combinator = new(tree.Combinator)('');
            }
            for (i = 0; i < p.length; i++) {
              if (p[i].isVisible() && p[i].getIsOutput()) {
                return true;
              }
            }
            return false;
          });
      }
    },

    _removeDuplicateRules: function(rules) {
      if (!rules) { return; }

      // remove duplicates
      var ruleCache = {},
        ruleList, rule, i;

      for (i = rules.length - 1; i >= 0 ; i--) {
        rule = rules[i];
        if (rule instanceof tree.Rule) {
          if (!ruleCache[rule.name]) {
            ruleCache[rule.name] = rule;
          } else {
            ruleList = ruleCache[rule.name];
            if (ruleList instanceof tree.Rule) {
              ruleList = ruleCache[rule.name] = [ruleCache[rule.name].toCSS(this._context)];
            }
            var ruleCSS = rule.toCSS(this._context);
            if (ruleList.indexOf(ruleCSS) !== -1) {
              rules.splice(i, 1);
            } else {
              ruleList.push(ruleCSS);
            }
          }
        }
      }
    },

    _mergeRules: function (rules) {
      if (!rules) { return; }

      var groups = {},
        parts,
        rule,
        key;

      for (var i = 0; i < rules.length; i++) {
        rule = rules[i];

        if ((rule instanceof tree.Rule) && rule.merge) {
          key = [rule.name,
            rule.important ? "!" : ""].join(",");

          if (!groups[key]) {
            groups[key] = [];
          } else {
            rules.splice(i--, 1);
          }

          groups[key].push(rule);
        }
      }

      Object.keys(groups).map(function (k) {

        function toExpression(values) {
          return new (tree.Expression)(values.map(function (p) {
            return p.value;
          }));
        }

        function toValue(values) {
          return new (tree.Value)(values.map(function (p) {
            return p;
          }));
        }

        parts = groups[k];

        if (parts.length > 1) {
          rule = parts[0];
          var spacedGroups = [];
          var lastSpacedGroup = [];
          parts.map(function (p) {
            if (p.merge === "+") {
              if (lastSpacedGroup.length > 0) {
                spacedGroups.push(toExpression(lastSpacedGroup));
              }
              lastSpacedGroup = [];
            }
            lastSpacedGroup.push(p);
          });
          spacedGroups.push(toExpression(lastSpacedGroup));
          rule.value = toValue(spacedGroups);
        }
      });
    },

    visitAnonymous: function(anonymousNode, visitArgs) {
      if (anonymousNode.blocksVisibility()) {
        return ;
      }
      anonymousNode.accept(this._visitor);
      return anonymousNode;
    }
  };

  module.exports = ToCSSVisitor;

},{"../tree":62,"./visitor":91}],91:[function(require,module,exports){
  var tree = require("../tree");

  var _visitArgs = { visitDeeper: true },
    _hasIndexed = false;

  function _noop(node) {
    return node;
  }

  function indexNodeTypes(parent, ticker) {
    // add .typeIndex to tree node types for lookup table
    var key, child;
    for (key in parent) {
      if (parent.hasOwnProperty(key)) {
        child = parent[key];
        switch (typeof child) {
          case "function":
            // ignore bound functions directly on tree which do not have a prototype
            // or aren't nodes
            if (child.prototype && child.prototype.type) {
              child.prototype.typeIndex = ticker++;
            }
            break;
          case "object":
            ticker = indexNodeTypes(child, ticker);
            break;
        }
      }
    }
    return ticker;
  }

  var Visitor = function(implementation) {
    this._implementation = implementation;
    this._visitFnCache = [];

    if (!_hasIndexed) {
      indexNodeTypes(tree, 1);
      _hasIndexed = true;
    }
  };

  Visitor.prototype = {
    visit: function(node) {
      if (!node) {
        return node;
      }

      var nodeTypeIndex = node.typeIndex;
      if (!nodeTypeIndex) {
        return node;
      }

      var visitFnCache = this._visitFnCache,
        impl = this._implementation,
        aryIndx = nodeTypeIndex << 1,
        outAryIndex = aryIndx | 1,
        func = visitFnCache[aryIndx],
        funcOut = visitFnCache[outAryIndex],
        visitArgs = _visitArgs,
        fnName;

      visitArgs.visitDeeper = true;

      if (!func) {
        fnName = "visit" + node.type;
        func = impl[fnName] || _noop;
        funcOut = impl[fnName + "Out"] || _noop;
        visitFnCache[aryIndx] = func;
        visitFnCache[outAryIndex] = funcOut;
      }

      if (func !== _noop) {
        var newNode = func.call(impl, node, visitArgs);
        if (impl.isReplacing) {
          node = newNode;
        }
      }

      if (visitArgs.visitDeeper && node && node.accept) {
        node.accept(this);
      }

      if (funcOut != _noop) {
        funcOut.call(impl, node);
      }

      return node;
    },
    visitArray: function(nodes, nonReplacing) {
      if (!nodes) {
        return nodes;
      }

      var cnt = nodes.length, i;

      // Non-replacing
      if (nonReplacing || !this._implementation.isReplacing) {
        for (i = 0; i < cnt; i++) {
          this.visit(nodes[i]);
        }
        return nodes;
      }

      // Replacing
      var out = [];
      for (i = 0; i < cnt; i++) {
        var evald = this.visit(nodes[i]);
        if (evald === undefined) { continue; }
        if (!evald.splice) {
          out.push(evald);
        } else if (evald.length) {
          this.flatten(evald, out);
        }
      }
      return out;
    },
    flatten: function(arr, out) {
      if (!out) {
        out = [];
      }

      var cnt, i, item,
        nestedCnt, j, nestedItem;

      for (i = 0, cnt = arr.length; i < cnt; i++) {
        item = arr[i];
        if (item === undefined) {
          continue;
        }
        if (!item.splice) {
          out.push(item);
          continue;
        }

        for (j = 0, nestedCnt = item.length; j < nestedCnt; j++) {
          nestedItem = item[j];
          if (nestedItem === undefined) {
            continue;
          }
          if (!nestedItem.splice) {
            out.push(nestedItem);
          } else if (nestedItem.length) {
            this.flatten(nestedItem, out);
          }
        }
      }

      return out;
    }
  };
  module.exports = Visitor;

},{"../tree":62}],92:[function(require,module,exports){
  "use strict";

// rawAsap provides everything we need except exception management.
  var rawAsap = require("./raw");
// RawTasks are recycled to reduce GC churn.
  var freeTasks = [];
// We queue errors to ensure they are thrown in right order (FIFO).
// Array-as-queue is good enough here, since we are just dealing with exceptions.
  var pendingErrors = [];
  var requestErrorThrow = rawAsap.makeRequestCallFromTimer(throwFirstError);

  function throwFirstError() {
    if (pendingErrors.length) {
      throw pendingErrors.shift();
    }
  }

  /**
   * Calls a task as soon as possible after returning, in its own event, with priority
   * over other events like animation, reflow, and repaint. An error thrown from an
   * event will not interrupt, nor even substantially slow down the processing of
   * other events, but will be rather postponed to a lower priority event.
   * @param {{call}} task A callable object, typically a function that takes no
   * arguments.
   */
  module.exports = asap;
  function asap(task) {
    var rawTask;
    if (freeTasks.length) {
      rawTask = freeTasks.pop();
    } else {
      rawTask = new RawTask();
    }
    rawTask.task = task;
    rawAsap(rawTask);
  }

// We wrap tasks with recyclable task objects.  A task object implements
// `call`, just like a function.
  function RawTask() {
    this.task = null;
  }

// The sole purpose of wrapping the task is to catch the exception and recycle
// the task object after its single use.
  RawTask.prototype.call = function () {
    try {
      this.task.call();
    } catch (error) {
      if (asap.onerror) {
        // This hook exists purely for testing purposes.
        // Its name will be periodically randomized to break any code that
        // depends on its existence.
        asap.onerror(error);
      } else {
        // In a web browser, exceptions are not fatal. However, to avoid
        // slowing down the queue of pending tasks, we rethrow the error in a
        // lower priority turn.
        pendingErrors.push(error);
        requestErrorThrow();
      }
    } finally {
      this.task = null;
      freeTasks[freeTasks.length] = this;
    }
  };

},{"./raw":93}],93:[function(require,module,exports){
  (function (global){
    "use strict";

// Use the fastest means possible to execute a task in its own turn, with
// priority over other events including IO, animation, reflow, and redraw
// events in browsers.
//
// An exception thrown by a task will permanently interrupt the processing of
// subsequent tasks. The higher level `asap` function ensures that if an
// exception is thrown by a task, that the task queue will continue flushing as
// soon as possible, but if you use `rawAsap` directly, you are responsible to
// either ensure that no exceptions are thrown from your task, or to manually
// call `rawAsap.requestFlush` if an exception is thrown.
    module.exports = rawAsap;
    function rawAsap(task) {
      if (!queue.length) {
        requestFlush();
        flushing = true;
      }
      // Equivalent to push, but avoids a function call.
      queue[queue.length] = task;
    }

    var queue = [];
// Once a flush has been requested, no further calls to `requestFlush` are
// necessary until the next `flush` completes.
    var flushing = false;
// `requestFlush` is an implementation-specific method that attempts to kick
// off a `flush` event as quickly as possible. `flush` will attempt to exhaust
// the event queue before yielding to the browser's own event loop.
    var requestFlush;
// The position of the next task to execute in the task queue. This is
// preserved between calls to `flush` so that it can be resumed if
// a task throws an exception.
    var index = 0;
// If a task schedules additional tasks recursively, the task queue can grow
// unbounded. To prevent memory exhaustion, the task queue will periodically
// truncate already-completed tasks.
    var capacity = 1024;

// The flush function processes all tasks that have been scheduled with
// `rawAsap` unless and until one of those tasks throws an exception.
// If a task throws an exception, `flush` ensures that its state will remain
// consistent and will resume where it left off when called again.
// However, `flush` does not make any arrangements to be called again if an
// exception is thrown.
    function flush() {
      while (index < queue.length) {
        var currentIndex = index;
        // Advance the index before calling the task. This ensures that we will
        // begin flushing on the next task the task throws an error.
        index = index + 1;
        queue[currentIndex].call();
        // Prevent leaking memory for long chains of recursive calls to `asap`.
        // If we call `asap` within tasks scheduled by `asap`, the queue will
        // grow, but to avoid an O(n) walk for every task we execute, we don't
        // shift tasks off the queue after they have been executed.
        // Instead, we periodically shift 1024 tasks off the queue.
        if (index > capacity) {
          // Manually shift all values starting at the index back to the
          // beginning of the queue.
          for (var scan = 0, newLength = queue.length - index; scan < newLength; scan++) {
            queue[scan] = queue[scan + index];
          }
          queue.length -= index;
          index = 0;
        }
      }
      queue.length = 0;
      index = 0;
      flushing = false;
    }

// `requestFlush` is implemented using a strategy based on data collected from
// every available SauceLabs Selenium web driver worker at time of writing.
// https://docs.google.com/spreadsheets/d/1mG-5UYGup5qxGdEMWkhP6BWCz053NUb2E1QoUTU16uA/edit#gid=783724593

// Safari 6 and 6.1 for desktop, iPad, and iPhone are the only browsers that
// have WebKitMutationObserver but not un-prefixed MutationObserver.
// Must use `global` or `self` instead of `window` to work in both frames and web
// workers. `global` is a provision of Browserify, Mr, Mrs, or Mop.

    /* globals self */
    var scope = typeof global !== "undefined" ? global : self;
    var BrowserMutationObserver = scope.MutationObserver || scope.WebKitMutationObserver;

// MutationObservers are desirable because they have high priority and work
// reliably everywhere they are implemented.
// They are implemented in all modern browsers.
//
// - Android 4-4.3
// - Chrome 26-34
// - Firefox 14-29
// - Internet Explorer 11
// - iPad Safari 6-7.1
// - iPhone Safari 7-7.1
// - Safari 6-7
    if (typeof BrowserMutationObserver === "function") {
      requestFlush = makeRequestCallFromMutationObserver(flush);

// MessageChannels are desirable because they give direct access to the HTML
// task queue, are implemented in Internet Explorer 10, Safari 5.0-1, and Opera
// 11-12, and in web workers in many engines.
// Although message channels yield to any queued rendering and IO tasks, they
// would be better than imposing the 4ms delay of timers.
// However, they do not work reliably in Internet Explorer or Safari.

// Internet Explorer 10 is the only browser that has setImmediate but does
// not have MutationObservers.
// Although setImmediate yields to the browser's renderer, it would be
// preferrable to falling back to setTimeout since it does not have
// the minimum 4ms penalty.
// Unfortunately there appears to be a bug in Internet Explorer 10 Mobile (and
// Desktop to a lesser extent) that renders both setImmediate and
// MessageChannel useless for the purposes of ASAP.
// https://github.com/kriskowal/q/issues/396

// Timers are implemented universally.
// We fall back to timers in workers in most engines, and in foreground
// contexts in the following browsers.
// However, note that even this simple case requires nuances to operate in a
// broad spectrum of browsers.
//
// - Firefox 3-13
// - Internet Explorer 6-9
// - iPad Safari 4.3
// - Lynx 2.8.7
    } else {
      requestFlush = makeRequestCallFromTimer(flush);
    }

// `requestFlush` requests that the high priority event queue be flushed as
// soon as possible.
// This is useful to prevent an error thrown in a task from stalling the event
// queue if the exception handled by Node.js’s
// `process.on("uncaughtException")` or by a domain.
    rawAsap.requestFlush = requestFlush;

// To request a high priority event, we induce a mutation observer by toggling
// the text of a text node between "1" and "-1".
    function makeRequestCallFromMutationObserver(callback) {
      var toggle = 1;
      var observer = new BrowserMutationObserver(callback);
      var node = document.createTextNode("");
      observer.observe(node, {characterData: true});
      return function requestCall() {
        toggle = -toggle;
        node.data = toggle;
      };
    }

// The message channel technique was discovered by Malte Ubl and was the
// original foundation for this library.
// http://www.nonblocking.io/2011/06/windownexttick.html

// Safari 6.0.5 (at least) intermittently fails to create message ports on a
// page's first load. Thankfully, this version of Safari supports
// MutationObservers, so we don't need to fall back in that case.

// function makeRequestCallFromMessageChannel(callback) {
//     var channel = new MessageChannel();
//     channel.port1.onmessage = callback;
//     return function requestCall() {
//         channel.port2.postMessage(0);
//     };
// }

// For reasons explained above, we are also unable to use `setImmediate`
// under any circumstances.
// Even if we were, there is another bug in Internet Explorer 10.
// It is not sufficient to assign `setImmediate` to `requestFlush` because
// `setImmediate` must be called *by name* and therefore must be wrapped in a
// closure.
// Never forget.

// function makeRequestCallFromSetImmediate(callback) {
//     return function requestCall() {
//         setImmediate(callback);
//     };
// }

// Safari 6.0 has a problem where timers will get lost while the user is
// scrolling. This problem does not impact ASAP because Safari 6.0 supports
// mutation observers, so that implementation is used instead.
// However, if we ever elect to use timers in Safari, the prevalent work-around
// is to add a scroll event listener that calls for a flush.

// `setTimeout` does not call the passed callback if the delay is less than
// approximately 7 in web workers in Firefox 8 through 18, and sometimes not
// even then.

    function makeRequestCallFromTimer(callback) {
      return function requestCall() {
        // We dispatch a timeout with a specified delay of 0 for engines that
        // can reliably accommodate that request. This will usually be snapped
        // to a 4 milisecond delay, but once we're flushing, there's no delay
        // between events.
        var timeoutHandle = setTimeout(handleTimer, 0);
        // However, since this timer gets frequently dropped in Firefox
        // workers, we enlist an interval handle that will try to fire
        // an event 20 times per second until it succeeds.
        var intervalHandle = setInterval(handleTimer, 50);

        function handleTimer() {
          // Whichever timer succeeds will cancel both timers and
          // execute the callback.
          clearTimeout(timeoutHandle);
          clearInterval(intervalHandle);
          callback();
        }
      };
    }

// This is for `asap.js` only.
// Its name will be periodically randomized to break any code that depends on
// its existence.
    rawAsap.makeRequestCallFromTimer = makeRequestCallFromTimer;

// ASAP was originally a nextTick shim included in Q. This was factored out
// into this ASAP package. It was later adapted to RSVP which made further
// amendments. These decisions, particularly to marginalize MessageChannel and
// to capture the MutationObserver implementation in a closure, were integrated
// back into ASAP proper.
// https://github.com/tildeio/rsvp.js/blob/cddf7232546a9cf858524b75cde6f9edf72620a7/lib/rsvp/asap.js

  }).call(this,typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{}],94:[function(require,module,exports){
  'use strict';

  var asap = require('asap/raw');

  function noop() {}

// States:
//
// 0 - pending
// 1 - fulfilled with _value
// 2 - rejected with _value
// 3 - adopted the state of another promise, _value
//
// once the state is no longer pending (0) it is immutable

// All `_` prefixed properties will be reduced to `_{random number}`
// at build time to obfuscate them and discourage their use.
// We don't use symbols or Object.defineProperty to fully hide them
// because the performance isn't good enough.


// to avoid using try/catch inside critical functions, we
// extract them to here.
  var LAST_ERROR = null;
  var IS_ERROR = {};
  function getThen(obj) {
    try {
      return obj.then;
    } catch (ex) {
      LAST_ERROR = ex;
      return IS_ERROR;
    }
  }

  function tryCallOne(fn, a) {
    try {
      return fn(a);
    } catch (ex) {
      LAST_ERROR = ex;
      return IS_ERROR;
    }
  }
  function tryCallTwo(fn, a, b) {
    try {
      fn(a, b);
    } catch (ex) {
      LAST_ERROR = ex;
      return IS_ERROR;
    }
  }

  module.exports = Promise;

  function Promise(fn) {
    if (typeof this !== 'object') {
      throw new TypeError('Promises must be constructed via new');
    }
    if (typeof fn !== 'function') {
      throw new TypeError('Promise constructor\'s argument is not a function');
    }
    this._40 = 0;
    this._65 = 0;
    this._55 = null;
    this._72 = null;
    if (fn === noop) return;
    doResolve(fn, this);
  }
  Promise._37 = null;
  Promise._87 = null;
  Promise._61 = noop;

  Promise.prototype.then = function(onFulfilled, onRejected) {
    if (this.constructor !== Promise) {
      return safeThen(this, onFulfilled, onRejected);
    }
    var res = new Promise(noop);
    handle(this, new Handler(onFulfilled, onRejected, res));
    return res;
  };

  function safeThen(self, onFulfilled, onRejected) {
    return new self.constructor(function (resolve, reject) {
      var res = new Promise(noop);
      res.then(resolve, reject);
      handle(self, new Handler(onFulfilled, onRejected, res));
    });
  }
  function handle(self, deferred) {
    while (self._65 === 3) {
      self = self._55;
    }
    if (Promise._37) {
      Promise._37(self);
    }
    if (self._65 === 0) {
      if (self._40 === 0) {
        self._40 = 1;
        self._72 = deferred;
        return;
      }
      if (self._40 === 1) {
        self._40 = 2;
        self._72 = [self._72, deferred];
        return;
      }
      self._72.push(deferred);
      return;
    }
    handleResolved(self, deferred);
  }

  function handleResolved(self, deferred) {
    asap(function() {
      var cb = self._65 === 1 ? deferred.onFulfilled : deferred.onRejected;
      if (cb === null) {
        if (self._65 === 1) {
          resolve(deferred.promise, self._55);
        } else {
          reject(deferred.promise, self._55);
        }
        return;
      }
      var ret = tryCallOne(cb, self._55);
      if (ret === IS_ERROR) {
        reject(deferred.promise, LAST_ERROR);
      } else {
        resolve(deferred.promise, ret);
      }
    });
  }
  function resolve(self, newValue) {
    // Promise Resolution Procedure: https://github.com/promises-aplus/promises-spec#the-promise-resolution-procedure
    if (newValue === self) {
      return reject(
        self,
        new TypeError('A promise cannot be resolved with itself.')
      );
    }
    if (
      newValue &&
      (typeof newValue === 'object' || typeof newValue === 'function')
    ) {
      var then = getThen(newValue);
      if (then === IS_ERROR) {
        return reject(self, LAST_ERROR);
      }
      if (
        then === self.then &&
        newValue instanceof Promise
      ) {
        self._65 = 3;
        self._55 = newValue;
        finale(self);
        return;
      } else if (typeof then === 'function') {
        doResolve(then.bind(newValue), self);
        return;
      }
    }
    self._65 = 1;
    self._55 = newValue;
    finale(self);
  }

  function reject(self, newValue) {
    self._65 = 2;
    self._55 = newValue;
    if (Promise._87) {
      Promise._87(self, newValue);
    }
    finale(self);
  }
  function finale(self) {
    if (self._40 === 1) {
      handle(self, self._72);
      self._72 = null;
    }
    if (self._40 === 2) {
      for (var i = 0; i < self._72.length; i++) {
        handle(self, self._72[i]);
      }
      self._72 = null;
    }
  }

  function Handler(onFulfilled, onRejected, promise){
    this.onFulfilled = typeof onFulfilled === 'function' ? onFulfilled : null;
    this.onRejected = typeof onRejected === 'function' ? onRejected : null;
    this.promise = promise;
  }

  /**
   * Take a potentially misbehaving resolver function and make sure
   * onFulfilled and onRejected are only called once.
   *
   * Makes no guarantees about asynchrony.
   */
  function doResolve(fn, promise) {
    var done = false;
    var res = tryCallTwo(fn, function (value) {
      if (done) return;
      done = true;
      resolve(promise, value);
    }, function (reason) {
      if (done) return;
      done = true;
      reject(promise, reason);
    });
    if (!done && res === IS_ERROR) {
      done = true;
      reject(promise, LAST_ERROR);
    }
  }

},{"asap/raw":93}],95:[function(require,module,exports){
  'use strict';

//This file contains the ES6 extensions to the core Promises/A+ API

  var Promise = require('./core.js');

  module.exports = Promise;

  /* Static Functions */

  var TRUE = valuePromise(true);
  var FALSE = valuePromise(false);
  var NULL = valuePromise(null);
  var UNDEFINED = valuePromise(undefined);
  var ZERO = valuePromise(0);
  var EMPTYSTRING = valuePromise('');

  function valuePromise(value) {
    var p = new Promise(Promise._61);
    p._65 = 1;
    p._55 = value;
    return p;
  }
  Promise.resolve = function (value) {
    if (value instanceof Promise) return value;

    if (value === null) return NULL;
    if (value === undefined) return UNDEFINED;
    if (value === true) return TRUE;
    if (value === false) return FALSE;
    if (value === 0) return ZERO;
    if (value === '') return EMPTYSTRING;

    if (typeof value === 'object' || typeof value === 'function') {
      try {
        var then = value.then;
        if (typeof then === 'function') {
          return new Promise(then.bind(value));
        }
      } catch (ex) {
        return new Promise(function (resolve, reject) {
          reject(ex);
        });
      }
    }
    return valuePromise(value);
  };

  Promise.all = function (arr) {
    var args = Array.prototype.slice.call(arr);

    return new Promise(function (resolve, reject) {
      if (args.length === 0) return resolve([]);
      var remaining = args.length;
      function res(i, val) {
        if (val && (typeof val === 'object' || typeof val === 'function')) {
          if (val instanceof Promise && val.then === Promise.prototype.then) {
            while (val._65 === 3) {
              val = val._55;
            }
            if (val._65 === 1) return res(i, val._55);
            if (val._65 === 2) reject(val._55);
            val.then(function (val) {
              res(i, val);
            }, reject);
            return;
          } else {
            var then = val.then;
            if (typeof then === 'function') {
              var p = new Promise(then.bind(val));
              p.then(function (val) {
                res(i, val);
              }, reject);
              return;
            }
          }
        }
        args[i] = val;
        if (--remaining === 0) {
          resolve(args);
        }
      }
      for (var i = 0; i < args.length; i++) {
        res(i, args[i]);
      }
    });
  };

  Promise.reject = function (value) {
    return new Promise(function (resolve, reject) {
      reject(value);
    });
  };

  Promise.race = function (values) {
    return new Promise(function (resolve, reject) {
      values.forEach(function(value){
        Promise.resolve(value).then(resolve, reject);
      });
    });
  };

  /* Prototype Methods */

  Promise.prototype['catch'] = function (onRejected) {
    return this.then(null, onRejected);
  };

},{"./core.js":94}],96:[function(require,module,exports){
// should work in any browser without browserify

  if (typeof Promise.prototype.done !== 'function') {
    Promise.prototype.done = function (onFulfilled, onRejected) {
      var self = arguments.length ? this.then.apply(this, arguments) : this
      self.then(null, function (err) {
        setTimeout(function () {
          throw err
        }, 0)
      })
    }
  }
},{}],97:[function(require,module,exports){
// not "use strict" so we can declare global "Promise"

  var asap = require('asap');

  if (typeof Promise === 'undefined') {
    Promise = require('./lib/core.js')
    require('./lib/es6-extensions.js')
  }

  require('./polyfill-done.js');

},{"./lib/core.js":94,"./lib/es6-extensions.js":95,"./polyfill-done.js":96,"asap":92}]},{},[2])(2)
});